Patent Publication Number: US-11656717-B2

Title: Sensor module and method for detecting and characterizing side inputs at devices

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application is a continuation of U.S. Non-Provisional patent application Ser. No. 17/339,857, filed on 4 Jun. 2021, which claims priority to U.S. Provisional Patent Application Nos. 63/053,071, filed on 17 Jul. 2020, and 63/034,798, filed on 4 Jun. 2020, each of which is hereby incorporated in its entirety by this reference. 
     This Application is related to U.S. patent application Ser. No. 14/499,001, filed on 26 Sep. 2014, which is hereby incorporated in its entirety by this reference. 
    
    
     TECHNICAL FIELD 
     This invention relates generally to the field of touch sensors and more specifically to new and useful systems and methods for detecting and characterizing side inputs at devices in the field of touch sensors. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG.  1    is a flowchart representation of a system; 
         FIGS.  2 A,  2 B, and  2 C  are schematic representations of one variation of the system; 
         FIG.  3    is a flowchart representation of one variation of the system; 
         FIG.  4    is a flowchart representation of one variation of the system; 
         FIG.  5    is a flowchart representation of one variation of the system; 
         FIG.  6    is a flowchart representation of one variation of the system; 
         FIG.  7    is a flowchart representation of one variation of the system; 
         FIG.  8    is a flowchart representation of one variation of the system; 
         FIGS.  9 A and  9 B  are a flowchart representation of one variation of the system; 
         FIG.  10    is a flowchart representation of one variation of the system; 
         FIGS.  11 A,  11 B, and  11 C  are schematic representations of one variation of the system; and 
         FIG.  12    is a schematic representation of one variation of the system. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     The following description of embodiments of the invention is not intended to limit the invention to these embodiments but rather to enable a person skilled in the art to make and use this invention. Variations, configurations, implementations, example implementations, and examples described herein are optional and are not exclusive to the variations, configurations, implementations, example implementations, and examples they describe. The invention described herein can include any and all permutations of these variations, configurations, implementations, example implementations, and examples. 
     1. System 
     As shown in  FIGS.  1 ,  11 A,  11 B, and  11 C , a system  100  includes: a frame  110 ; a sensor module  120 ; and a controller  150 . The frame  110  includes: a base structure  112  configured to locate a display  182  that defines a front face of a mobile computing device; and a lateral frame structure  114  extending along and adjacent a first edge of the display  182  and supported on a first side of the base structure  112 . The base structure  112  and the lateral frame structure  114  cooperate to define a channel  116 : arranged behind the display  182 ; and extending longitudinally between the lateral frame structure  114  and the first side of the base structure  112 . The sensor module  120  is arranged in the channel  116  and includes: a substrate  121 ; and a linear array of sensors  124  arranged on the substrate  121  and configured to output sense signals representing local deflections of the lateral frame structure  114 . The controller  150  is configured to detect locations and force magnitudes of side inputs on the mobile computing device, proximal the first edge of the display  182 , based on sense signals output by the linear array of sensors  124 . 
     2. Applications 
     Generally, the system  100  can be integrated into a mobile computing device (e.g., a smartphone, a tablet, a laptop computer) to form a continuous pressure sensor along one or more sides of the mobile computing device and thus enable the mobile computing device (hereinafter the “device”) to detect both force magnitudes and locations of inputs along the side of the device  170  (hereinafter “side inputs”) over a range of force magnitudes and over a (nearly-) continuous range of location. In particular, the system  100  can include: a sensor module  120  arranged behind side of a device  170 ; and a controller  150  that detects locations and force magnitudes of inputs on the side of the device  170  based on sense signals output by the sensor module  120 , dynamically links these side inputs to particular input types based on these input characteristics and/or virtual buttons  188  rendered on a display  182  of the device  170  adjacent the locations of these side inputs, and then triggers context-dependent (e.g., application-specific) command functions at the device  170  based on these input types. For example, the sensor module  120  can be integrated into a side of a device  170  (e.g., in place of mechanical buttons) in order to transform the perimeter of the device  170  into a force-sensitive input surface. The controller  150  (or other processor in the device  170 ) can then dynamically reassign regions or segments of the side of the device  170  to different input types (e.g., volume control, camera shutter control) based on: a lock screen, home screen, or application open on the device  170 ; an orientation of the device  170 ; a last touch location on the side of the device  170 ; and/or custom settings entered by the user. 
     2.1 Hardware Assembly and Configuration 
     More specifically and as shown in  FIGS.  2 A,  2 B, and  2 C , the sensor module  120  can include a set of force-sensitive elements—such as a set of drive electrodes and corresponding sense electrodes (hereinafter “drive and sense electrode pairs  125 ”)—arranged on a strip of flexible substrate  121  of length approximating (e.g., within 80% of) the length of a side of the device  170 , arranged under a front display of the device  170 , located behind a structure defining this side of the device  170  (e.g., a curved section of the display  182 , a segment of a frame  110  of the device  170 ). For example, the sensor module  120  can include: flexible substrate  121  a 250-microns in thickness, 7 millimeters in width, 150 millimeters in length, and populated with a single column of 20 drive and sense electrode pairs  125 ; and a force-sensitive layer  126  laminated across the column of drive and sense electrode pairs  125  and exhibiting variations in contact resistance against the drive and sense electrode pairs  125  (or variations in local bulk resistance) responsive to local variations in applied force. A channel  116  can be machined, cast, or molded, etc. along and inset from a side of a frame  110  of the device  170  (e.g., along 90% of the length of the side of the frame  110  and inset 1.5 millimeters from the side of the frame  110 ). 
     During assembly of the device  170 , this preassembled sensor module  120  and an elastic compression element  128  (e.g., a foam insert) can be inserted into the channel  116 . A set of shims  160  can then be installed between the sensor module  120  and the channel  116 : to compress the compression element  128  (which fills voids and consumes a manufacturing tolerance stack across the channel  116 ); and to preload the force-sensitive layer  126  against the sensor module  120 . More specifically, the compression element  128  can: depress the sensor module  120  against an interior wall of the channel  116 ; deform to fill voids between the sensor module  120  and the channel  116 ; absorb inconsistencies and/or manufacturing defects within the channel  116  and on the sensor module  120 ; exert a pre-load force (i.e., a compressive force) across the sensor module  120  to eliminate gaps between the force-sensitive layer  126  and the drive and sense electrode pairs  125 ; and thus extend a lower end of the dynamic range of the sensor module  120  along its full length. 
     As shown in  FIG.  1   , a planar display can then be installed in the frame  110  to enclose the channel  116  such that an edge of the display  182  terminates proximal (e.g., within 0.5 millimeter of) the side of the frame  110  (i.e., over the lateral frame structure  114  between the channel  116  and the side of the device  170 ). Accordingly, a section of the lateral frame structure  114  extending along the channel  116  can define a side of the device  170  and can deflect inwardly into the channel  116 —and thus compress the force-sensitive layer  126  and modify the contact resistance of the force-sensitive layer  126  against the column of drive and sense electrode pairs  125 —responsive to application of a force on the side of the device  170 , such as: a user depressing a thumb or forefinger against a region of the side of the device  170  assigned to a virtual volume control or virtual shutter control; or a user squeezing the sides of the device  170  (e.g., to silence an inbound phone call). More specifically, a drive and sense electrode pair can output a sense signal representing contact resistance with an adjacent region of the force-sensitive layer, which changes as a function of contact area of the force-sensitive layer against the drive and sense electrode pair, which changes as a function of applied force. For example, the sense signal output by the sense electrode can represent a sum of many parallel resistances across the local region of the force-sensitive layer in contact with the drive and sense electrode pair. 
     A controller  150  coupled to the sensor module  120  can thus: read sense signals (e.g., resistance values) from the column of drive and sense electrode pairs  125 ; interpret force magnitudes carried into each of the drive and sense electrode pairs  125  based on these sense signals, interpret a force gradient along the side of the device  170  based on these force magnitudes, detect locations and force magnitudes of individual inputs along this side of the device  170  based on this force gradient, and/or trigger actions assigned to inputs of these force magnitudes and/or at these locations along the side of the device  170 . 
     Alternatively, a non-planar (i.e., curved) display can be installed over the frame  110  with a curved section of the display  182  extending over and enclosing a side of the frame  110  and the channel  116 . Accordingly, the curved section of the display  182  and the frame  110  can collectively deflect inwardly responsive to inputs along the side of the device  170 , thereby locally compressing the force-sensitive layer  126 , locally changing (e.g., decreasing) the contact resistance between the force-sensitive layer  126  and the column of drive and sense electrode pairs  125 , and modifying sense signals output by the drive and sense electrode pairs  125 . The controller  150  can then detect and interpret side inputs on the device  170  based on these sense signals. 
     Yet alternatively, a curved section of a non-planar display can cooperate with the frame  110  to define the channel  116  thus occupied by (or “stuffed with”) the sensor module  120 , as shown in  FIGS.  9 A and  9 B . Accordingly, the curved section  186  of the display  182  deflect inwardly into the channel  116  responsive to inputs along the side of the device  170 , thereby locally compressing the force-sensitive layer  126 , locally changing (e.g., decreasing) the contact resistance between the force-sensitive layer  126  and the column of drive and sense electrode pairs  125 , and modifying sense signals output by the drive and sense electrode pairs  125 . The controller  150  can then detect and interpret side inputs on the device  170  based on these sense signals. 
     2.2 Side Input Detection 
     In particular, during operation, side inputs into the device  170  can inwardly deflect local regions of the side of the device  170  (e.g., the lateral frame structure  114 , a curved section  186  of the display  182 ), which locally compresses the force-sensitive material, which changes (e.g., decreases) contact resistance across one or more adjacent pairs of drive and sense electrode pairs  125 . The controller  150  can thus detect these changes in resistance across these drive and sense electrode pairs  125  and interpret magnitudes of forces carried into the device  170  through these drive and sense electrode pairs  125  as a function of (e.g., proportional to) magnitudes of deviations of sense signals (e.g., magnitudes of changes in voltages or resistances)—read from these drive and sense electrode pairs  125 —from corresponding baseline values. 
     The controller  150  can also: interpolate force magnitudes between these drive and sense electrode pairs  125 ; calculate a force gradient across the sensor module  120 ; isolate locations (e.g., centers, centroids) of discrete side inputs; detect side inputs of force magnitudes that exceed threshold forces; interpret sizes (i.e., lengths) of side inputs; etc. based on magnitudes of forces detected at each drive and sense electrode pair  125  in the sensor module  120 . 
     2.3 Virtual Button Reallocation 
     Furthermore, the controller  150  can: dynamically associate pre-programmed command functions to discrete regions along the side of the device  170 ; define size (E.g., length) and/or force magnitude thresholds for triggering these functions responsive to side inputs near these discrete regions; and then selectively trigger or execute these command functions based on side inputs interpreted from sense signals read from the sensor module  120 . 
     For example, the controller  150  can characterize a gesture represented by a side input, such as: by matching an instantaneous force gradient captured during a single sensor module  120  scan cycle to a stored force gradient template (e.g., squeezing the side of the device  170  to silence an inbound phone call); or by matching a sequence of force gradients captured during a sequence of scan cycles to a stored force gradient template (e.g., drawing a finger along the side of the device  170  to scroll down a document or webpage). The controller  150  can then execute an action linked to this matched gesture. 
     Similarly, the controller  150  can: dynamically remap locations and/or sensing areas on the side of the device  170  to different or additional command functions (e.g., basic commands associated with a lock screen, a home screen, or an application that is currently executing on the device  170 ); and trigger the display  182  to render icons for these command functions adjacent the current locations and/or sensing areas on the side of the device  170  currently linked to these command functions, as shown in  FIGS.  5  and  6   . The controller  150  can thus dynamically reallocate particular command functions to different regions along the side of the device  170  in order to seamlessly support a variety of diverse, context-dependent functionalities. 
     Thus, the sensor module  120  and the controller  150  can: augment and/or replace functionalities of mechanical buttons—such as power-on, volume, scrolling, camera shutter, gaming, and/or video playback controls; and enable dynamic reallocation of regions of the side of the device  170  linked to these functions. 
     3. Device and Frame 
     In one implementation shown in  FIG.  1   , the device  170  (e.g., a mobile phone, a tablet, a smartwatch, a laptop computer) includes: a display  182  (e.g., a flat LCD display or touchscreen  180 , a curved OLED display or touchscreen  180 ); a frame  110  (or a “midframe  110 ”, a chassis) configured to support the display  182  and defining a channel  116  extending along a side (e.g., a left or right lateral side) of the device  170  adjacent and behind an edge of the display  182 ; a rear cover coupled to the frame  110  opposite the display  182 ; and a set of electronic components (e.g., a processor, a battery, a wireless communication module, memory, etc.) arranged inside of and supported on the frame  110 . 
     As described below, the frame  110  can include a machined, cast, forged, sintered, and/or molded aluminum, steel, or polymer structure. Furthermore, the perimeter of the frame  110  can be exposed about the perimeter of the display  182  and thus define external, tactile surfaces of the device  170 . 
     In one implementation, the frame  110  includes: a base structure  112  configured to locate the display  182 , which defines a front face of the device  170 ; and a lateral frame structure  114  that extends along and adjacent a first edge of the display  182 , is supported on a first side of the base structure  112 , and cooperates with the base structure  112  to define a channel  116  arranged behind the display  182  and extending longitudinally between the lateral frame structure  114  and the first side of the base structure  112 . 
     For example, the frame  110  can include a 5-millimeter-thick, 150-millimeter-long unitary machined aluminum structure, including a machined aluminum slot: extending into the frame  110  perpendicular to a front planar face of the display  182 ; extending longitudinally along a first lateral side of the frame  110  to form the channel  116  that is 140 millimeters in length, 4.5-millimeters in depth, and 1.5 millimeters wide; inset from the first lateral side of the frame  110  to form the lateral frame structure  114  that is 1 millimeter thick, 4.5 millimeters tall, and 140 millimeters long and supported off of the base structure  112  by a 0.5-millimeter-thick web (or “rib”) running along the base of the channel  116 . The sensor module  120  can then be inserted into this channel  116 . 
     Furthermore, in this example, because a rear edge of the lateral frame structure  114  (e.g., adjacent a rear cover panel  174  of the device  170 ) is retained and supported by the web, the front edge of the lateral frame structure  114 —adjacent the display  182 —can preferentially deflect inwardly toward the base structure  112  of the frame  110  to transfer forces input on this side of the device  170  into the sensor module  120 , such as to compress a force-sensitive layer  126  against the drive and sense electrode pairs  125  in the sensor module  120  responsive to forces applied to this side of the device  170 . For example, the front edge of the lateral frame structure  114 —adjacent an edge of the display  182 —can be configured to locally deflect inwardly toward the first side of the base structure  112  by a distance between 0.0005 inch and 0.002 inch per pound of force applied to a local section of the side of the mobile computing device. Accordingly, the force-sensitive layer  126  can exhibit local changes in contact resistance inversely proportional to local inward deflection of the front edge of the lateral frame structure  114 , which the drive and sense electrode pairs  125  and the controller  150  can detect and interpret as locations and/or force magnitudes of side inputs on the device  170 . The thickness of the web can thus be set (or “tuned”) to achieve a target rate of deflection of the front edge of the lateral frame structure  114  per unit of force applied to the side of the device  170  in order to achieve a target sensitivity to side inputs on the device  170 . Additionally or alternatively, the web can be perforated, as described below, to form a series of bridges along the base of the channel  116 , which may reduce resistance to forces applied to the lateral frame structure  114  and thus increase sensitivity of the system  100  to side inputs on the device  170 . 
     4. Sensor Module 
     The sensor module  120  is arranged in the channel  116  and includes: a substrate  121 ; and a linear array of sensors  124  arranged on the substrate  121  and configured to output sense signals representing local deflections of the lateral frame structure  114 . 
     In one implementation shown in  FIG.  2 A , the sensor module  120  includes a force-sensitive layer  126  that faces (e.g., is laminated across) the substrate  121  and that exhibits local changes in contact resistance responsive to local compression against the sensor module  120 . Each sensor in the linear array of sensors  124  in the sensor module  120 : can include a drive and sense electrode pair  125  facing a region of the force-sensitive layer  126 ; and can output a sense signal (e.g., a voltage) representing contact resistance of the adjacent region of the force-sensitive layer  126  between the drive and sense electrode pair  125 . In particular, the set of drive and sense electrode pairs  125  can be fabricated across or installed on the substrate  121  (e.g., a rigid or flexible PCB). The force-sensitive layer  126 : can be arranged over the set of drive and sense electrode pairs  125 ; can be bonded to the perimeter of the substrate  121 ; and can include a material that exhibits variations in contact resistance against the drive and sense electrode pairs  125  (or variations in local bulk resistance) as a function of applied force (e.g., local compression). 
     In the example above in which the frame  110  defines a 140-millimeter-long channel  116  in a 150-millimeter-long device, the sensor module  120  can include a 138-millimeter-long substrate  121  populated with 24 drive and sense electrode pairs  125  and can be arranged in the channel  116  approximately perpendicular to the front planar face of the display  182 . A compression element  128  can also be inserted into the channel  116  adjacent the sensor module  120 : to fill gaps between the sensor module  120  and walls of the channel  116 ; and to cooperate with the frame  110  to communicate forces incident on the side of the device  170  (e.g., on the lateral frame structure  114 ) into local compression of the force-sensitive layer  126  against the sensor module  120 , which yields changes in sense signals output by sense electrode pairs near these forces. The controller  150  can then detect locations and/or force magnitudes of inputs on this side of the device  170  based on these sense signal changes. 
     4.1 Drive and Sense Electrode Pair Arrangement 
     In one implementation shown in  FIG.  2 B , the set of drive and sense electrode pairs  125  are arranged in single column extending along the length of substrate  121 . In one example, the sensor module  120  includes: 24 rows of 24 drive electrodes arranged in a single column and connected to a single common drive line; and 24 sense electrodes arranged in the single column, each connected to one of 24 sense lines. In this example, during a scan cycle, the controller  150  can selectively drive the single common drive line and serially read a sense signal from each of the 24 sense lines. In another example, the sensor module  120  includes: six clusters of four drive electrodes arranged in one row, wherein each cluster of drive electrodes is connected to one of six common drive lines; and six clusters of four sense electrodes arranged in the row, wherein each cluster of sense electrodes is connected to one of six common sense lines and includes one sense electrode paired with a drive electrode in each of the six cluster of drive electrodes. In this example, during a scan cycle, the controller  150  can: selectively drive the first common drive line and serially read each of the six common sense lines to capture sense signals from the first cluster sense electrodes; selectively drive the second common drive line and serially read each of the six common sense lines to capture sense signals from the second cluster sense electrodes; selectively drive the third common drive line and serially read each of the six common sense lines to capture sense signals from the third cluster sense electrodes; etc. 
     4.2 Force-Sensitive Layer Arrangement 
     In one implementation shown in  FIGS.  2 A and  3   , the force-sensitive layer  126  is bounded about a perimeter of the substrate  121  with an adhesive (e.g., an annular or “ring” adhesive layer). In this implementation, the adhesive can cover a region of the sensor module  120  and thus reduce sensitivity of the sensor module  120  to forces applied to corners of the device  170  such that the sensor module preferentially detects forces applied squarely to the side of the device. Accordingly, the sensor module may be less sensitive to falsely interpreting a hand holding the device  170  as an input into the side of the device. 
     In another implementation shown in  FIG.  1   , the force-sensitive layer  126  is wrapped around the substrate. In this implementation, the force-sensitive layer  126  also be bonded to the back side of the substrate  121  opposite the sensors  124  such that the force-sensitive layer faces and is exposed to the full height and width of the sensors  124  on the front side of the substrate  110 . Accordingly, in this implementation, the sensor module may exhibit sensitivity to both forces applied to corners of the device  170  and forces applied squarely to the side of the device. 
     4.? Controller Integration 
     As shown in  FIG.  2 C , the controller  150  can be arranged remotely from the set of drive and sense electrode pairs  125 . For example, the substrate  121  can include: a (rectangular) sense section  122  configured to insert into the channel  116  in the frame  110  and to extend longitudinally along the side of the device  170 ; and a “tail” section  123  extending laterally from the sense section  122  and defining a plug configured to insert into a data and power receptacle on a main board of the device  170 . In this example, the controller  150  can be mounted to the tail section  123  and can communicate locations and/or force magnitudes of detected side inputs into the device  170  (e.g., a processor on the main board of the device  170 ) via the plug such that the sensor module  120  and the controller  150  define a singular structure configure to install simply in the device  170  (i.e., by inserting the sense section  122  into the channel  116 , loading a compression element  128  and a set of shim  160  into the channel  116 , and then connecting the tail section  123  to a receptacle on a main board of the device  170 ). 
     Therefore, in this variation, the sensor module  120  and the controller  150  can be fabricated and/or assembled on a single structure (e.g., a single, unitary flexible PCB) to form a self-contained side-input detection and interpretation subsystem that includes: a sense section  122  configured to install in the channel  116  and retained without adhesives; and tail section  123  configured to insert a receptacle within the device  170  to fully connect the sensor module  120  and the controller  150  to power supply and data input/output terminals within the device  170 . 
     5. Channel Configuration and Bridges 
     In one variation shown in  FIGS.  11 A,  11 B, and  11 C , the frame  110  further defines a series of bridges: extending across the channel  116  from the first side of the base structure  112  to the lateral frame structure  114 ; longitudinally offset along the channel  116 ; and configured to locate a rear edge of the lateral frame structure  114  on the base structure  112 . More specifically, rather than a continuous web extending from the base structure  112  of the frame  110  to the lateral frame structure  114 , the frame  110  can include discrete, intermittent “bridges” that support and locate the rear edge of the lateral frame structure  114  on the base structure  112 . In this variation, each sensor in the sensor module  120 : can be longitudinally centered between a pair of adjacent bridges—in this series of bridges—in the channel  116 ; and can output a sense signal representing local deflection of the adjacent section of the lateral frame structure  114  between this pair of adjacent bridges. 
     These bridges can thus: enable a front edge of the lateral frame structure  114 —adjacent the display  182 —to preferentially deflect inwardly toward the base structure  112  responsive to side inputs applied to this side of the mobile computing device; and/or enable greater inward deflection of regions of the lateral frame structure  114  between these bridges per unit force applied to the side of the device  170  over these regions of the lateral frame structure  114 . More specifically, the bridges can exhibit greater yield to per unit force applied to the side of the device  170  such that greater proportions of forces applied to the side of the device  170  are carried into the sensor module  120 , which produces greater compression of the force-sensitive layer  126  and thus greater changes in local contact resistance of the force-sensitive layer  126 . Accordingly, the sensors can output sense signals exhibiting greater changes in amplitude per unit force applied to the side of the device  170 , thereby increasing sensitivity of the system  100 . 
     5.1 Example: Aluminum Frame with Exposed Side Faces 
     In one example implementation shown in  FIG.  1   , the frame  110  includes a 5-millimeter-thick aluminum structure with sides that are exposed when the display  182  and rear cover panel  174  are installed on the front and rear of the frame  110 , respectively. In this example implementation, the frame  110  is diecast, machined, and/or extruded, etc. to form a 1.5-millimeter-wide, 4-millimeter deep linear, rectangular channel  116 —inset by 1 millimeter from a front edge of a first side of the frame  110 . A row of elongated slots are then machined or punched through the base of the channel  116  (e.g., a 1-millimeter-thck web) at positions along the length of the channel  116  corresponding to sensing areas of the sensor module  120  to form a row of “bridges” extending across the base of the channel  116  to support the lateral frame structure  114  between these sensing areas. 
     In another example in which the first side of the frame  110  is 150-millimeters-long, the channel  116  can be 120 millimeters in length (i.e., 80% of the length of the frame  110 ), including twenty 5-millimeter-long slots machined along the base of the channel  116  through to the rear face of the frame  110  at 6-millimeter pitch distances to form nineteen 1-millimeter-wide “bridges” at 6-millimeter pitch intervals along the base of the channel  116 . In this example, the sensor module  120 : can be approximately 120 millimeters (e.g., 118 millimeters) in length; can define a row of twenty sense areas—each containing one or a group of drive and sense electrode pairs  125 —at 6-millimeter pitch distances along its length; and can be arranged in the channel  116  such that regions of the sensor module  120  between adjacent sense areas face these bridges. 
     Thus, the row of bridges can resist deflection of the rear edge of this side of the frame  110  when a force is applied to this side of the frame  110  (e.g., when the device  170  is “squeezed”) by a user. However, unsupported segments of the side of the frame  110  between two adjacent bridges may deflect (i.e., bend) inwardly when squeezed by the user. A force applied to an unsupported segment of the side of the frame  110  may deflect this unsupported frame  110  segment inwardly toward the adjacent sensing area of the sensor module  120 , thereby: transferring (a portion of) this force into the sensor module  120 ; compressing the force-sensitive material of the sensor module  120 ; and reducing local bulk resistance of the force-sensitive material. The controller  150  can then: detect this reduction in local bulk resistance of the force-sensitive material in the form of a change in resistance across sense and drive electrodes in this sensing area of the sensor module  120 ; and transform the magnitude of this change in resistance into a force magnitude of an input at the position of this sensing area along the first side  171  of the device  170 . 
     More specifically, these bridges can function to: consistently locate the rear edge of the first side of the frame  110 ; maintain a consistent width of the back face of the frame  110 ; and enable preferential inward elastic deflection of the front edge of the first side of the frame  110  and inward elastic deflection of unsupported segments of the first side of the frame  110  between bridges toward the sensor module  120 —thereby enabling the touch senor module and the controller  150  to detect and interpret a force magnitude of an input applied to the first side  171  of the device  170 . 
     Furthermore, the bridges—spanning the base of the channel  116 —can reduce sensitivity to inputs along the rear edge of the first side  171  of the device  170  and/or enable higher sensitivity to inputs along the front edge of the first side  171  of the device  170 . For example, the device  170  can render virtual icons along the edge of the display  182  adjacent the first edge of the frame  110  to indicate commands or actions (currently) associated with different regions of the first side  171  of the device  170 . Upon seeing these virtual icons rendered on the display  182 , a user may be inclined to preferentially “squeeze” or depress the first side  171  of the device  170  nearer the front edge of the device  170  to input a command associated with an adjacent virtual icon rendered on the display  182 . Thus, because the bridges are arranged along the rear edge of the first side  171  of the device  170 , the front edge of the first side of the frame  110  can exhibit a lower spring constant than the rear edge of the first side of the frame  110  such that the former deflects more under an applied force and such that more of this applied force is transferred into and detected by the sensor module  120 . 
     (Alternatively, to achieve preferential force detection along the rear edge of the first side of the frame  110 , the channel  116  can extend forward from the rear face of the frame  110  toward the display  182 , and the bridges can be formed along the front face of the frame  110 .) 
     Therefore, in this variation: the base structure  112 , the lateral frame structure  114 , and the series of bridges can define a unitary structure (e.g., metallic structure); and a base of the channel  116 —opposite the display  182 —can be perforated to form a series of bridges that support the lateral frame structure  114  off of the base structure  112  of the frame  110 . 
     5.2 Example: Steel Frame 
     In another example implementation, the frame  110  includes a 5-millimeter-thick stainless steel structure and a rectangular channel  116 : machined along the top face of the frame  110 ; 1.5-millimeter-wide; 4.5-millimeter deep linear; and inset by 0.6 millimeter from the front edge of the first side of the frame  110 . 
     In one example in which the first side of the frame  110  is 150-millimeters-long, the channel  116  can be 120 millimeters in length, including fifteen 7.5-millimeter-long slots machined along the base of the channel  116  through to the back face of the frame  110  at 8-millimeter pitch distances to form fourteen 0.5-millimeter-wide “bridges” at 8-millimeter intervals along the base of the channel  116 . In this example, the sensor module  120  is approximately 120 millimeters in length, defines a row of twenty sense areas at 6-millimeter pitch distances along its length, and is installed in the channel  116 , as described further below. 
     In particular, by reducing the thickness of the unsupported segments of the first side of the frame  110  and reducing the width and thickness of the bridges, the stainless steel frame  110  can exhibit spring constants along the front edge of the first side of the frame  110  and along the unsupported segments of the first side of the frame  110  similar to the aluminum frame  110  described above. 
     Conversely, by increasing the thickness of the unsupported segments of the first side of the frame  110  and/or increasing the width and thickness of the bridges, a plastic or polymer frame  110  may exhibit spring constants along the front edge of the first side of the frame  110  and along the unsupported segments of first side of the frame  110  similar to the aluminum and stainless steel frames described above. 
     6. Sensor Module Assembly 
     In this variation and as described above, the sensor module  120  can include: a substrate  121  (e.g., a flexible PCB); a set of drive and sense electrodes  125  arranged across the substrate  121  (e.g., fabricated on one or more conductive layers of the flexible PCB); a layer of force-sensitive material arranged over the substrate  121  adjacent the set of drive and sense electrodes and exhibiting local changes in bulk resistance as a function of applied force (or pressure); and a compression element  128  (e.g., a foam slip) arranged across the force-sensitive material opposite the substrate  121  and configured to fill a void between the channel  116  and the sensor module  120 . 
     In one implementation, the sensor module  120  also includes a first tapered shim  160  bonded to the substrate  121  opposite the force-sensitive material, such as with a pressure-sensitive adhesive—such that a thick end of the first tapered shim  160  extends along a rear edge of the substrate  121 . In this implementation, the sensor module  120  is inserted into the channel  116  in the frame  110  with the rear edge of the substrate  121  and the thick end of the first tapered shim  160  located in the bottom of the channel  116  adjacent the rear face of the frame  110 . A second tapered shim  160 —similar in geometry to the first tapered shim  160 —is then inserted, thin-end first, into the channel  116  between the first tapered shim  160  and the adjacent inner wall of the channel  116 , thereby driving the sensor module  120  toward the opposite inner wall of the channel  116  and compressing the compression element  128  to fill voids and geometric inconsistencies along the channel  116 . 
     For example, for a 1.5-millimeter-wide channel  116  described above: the substrate  121  can define a thickness of 0.3 millimeters; the pressure-sensitive material layer can define a thickness of 0.3 millimeters; the compression element  128  can define a thickness of 0.4 millimeters; and the pressure-sensitive adhesive can define a thickness of 0.1 millimeters. Furthermore, the first and second tapered shims  160  can include: thin ends 0.2 millimeters in thickness; and thick ends 0.4 millimeters in thickness. The total uninstalled stack height of these elements is therefore approximately 1.7 millimeters. However, the total installed stack height of these elements—once installed in the channel  116 —is 1.5 millimeters, including compression of the compression element  128  from an original thickness of 0.4 millimeters to a nominal final thickness of 0.2 millimeters. 
     Alternatively, in a similar example shown in  FIGS.  1  and  3   , the sensor module  120  and the compression element  128  can be installed in the channel  116 , and a set of flat or tapered shims  160  (e.g., two 0.3-millimeter-thick shims  160 ) can then be installed in the channel  116  (e.g., between a face of the channel  116  and the substrate  121  of the sensor module  120 ) to compress the compression element  128  and to drive the force-sensitive layer  126  in contact with the substrate  121 . 
     A display  182  and rear cover panel  174  can then be bonded and/or sealed against a perimeter of the frame  110 —beyond these channels  116  and sensor modules  120 —such that these channels  116  and sensor modules  120  fall within the waterproof or water-resistant envelope formed by the frame  110 , the display  182 , and the rear cover panel  174 . 
     7. Multiple Sensor Modules Per Side of Device 
     In one variation, the system  100  includes: a front channel  116  formed along the front face of the frame  110  adjacent the first side of the frame  110 ; a rear channel  116  formed along the rear face of the frame  110  adjacent the first side of the frame  110  and at a depth similar to the front channel  116  to form a web proximal a mid-plane of the frame  110 ; a row of through-slots formed along the web to form a row of bridges between the front and rear channels  116 ; a front sensor module  120  installed in the front channel  116 ; and a rear sensor module  120  similarly installed in the rear channel  116 . 
     In this variation, a front edge of the lateral frame structure  114  may preferentially deflect inwardly toward the front sensor module  120  when a force is applied near the front edge of this side of the frame  110 , which is then preferentially detected by the front sensor module  120 . Similarly, a rear edge of the lateral frame structure  114  may preferentially deflect inwardly toward the rear sensor module  120  when a force is applied near the rear edge of this side of the frame  110 , which is then preferentially detected by the rear sensor module  120 . Therefore, in this variation, the controller  150  can detect and distinguish between forces applied along the front and rear edges of this side of the frame  110  and selectively execute actions according to such front or rear side inputs into the device  170 . 
     For example, the controller  150  can: detect inputs along both the front and rear edges of this side of the device  170  based on sense signals read from sensors in the front and rear sensor modules  120 ; identify a rear side input at a particular location on this side of the device  170  if the force magnitude detected by a sensor in the rear sensor module  120  at this particular location is greater than the force magnitude detected by the adjacent sensor in the front sensor module  120  at this particular location; and vice versa. The controller  150  can then: read side inputs as a hand or fingers gripping the device  170  and thus ignore these side inputs; and interpret front side inputs as intentional inputs and thus trigger actions responsive to front side inputs. In this example, the controller  150  can thus enable the user to: hold the device  170  without triggering an action; and then trigger a particular action be depressing a section of the front edge of this side of the device  170  near a virtual button  188 —associated with this particular action—rendered on the display  182 . 
     8. Sensor Modules on Multiple Sides of Device 
     Additionally or alternatively, the device  170  can include channels  116  and sensor modules  120  arranged along additional sides of the frame  110 , such as: along the left and right sides of the device  170 ; or on the left, right, and top sides of the device  170 , as shown in  FIGS.  1  and  10   . 
     In one implementation, the frame  110  further includes a second outer frame structure  130  (e.g., a second lateral frame structure  114 ): extending along and adjacent a second edge of the display  182  (e.g., a top side of the device  170 ); a second lateral side of the device  170  opposite the (first) channel  116  and the (first) sensor module  120 ; supported on a second side of the base structure  112  of the frame  110 ; and cooperating with the base structure  112  to define a second channel  136  arranged behind the display  182  and extending between the second outer frame structure  130  and the second side of the base structure  112 . In this implementation, the system  100  also includes a second sensor module  140  arranged in the second channel  136  and including: a second substrate  141 ; and a second linear array of sensors  124  arranged on the second substrate  141  and configured to output sense signals representing local deflections of the second outer frame structure  130 . 
     In this implementation, the controller  150  can be further configured to detect locations and force magnitudes of side inputs on the mobile computing device—proximal the second edge of the display  182 —based on sense signals output by the second linear array of sensors  124 . More specifically, in this implementation, the controller  150  can sample sense signals from sensors in both sensor modules  120  and interpret locations and force magnitudes of inputs on both of these sides of the device  170  based on these sense signals. 
     Alternatively, in this implementation, the system  100  can include a second controller  150  coupled to the second sensor module  140  and executing methods and techniques described above and below to detect and interpret force magnitudes of inputs solely on the second side  172  of the device  170  based on sense signals read from sensors in the second sensor module  140 . 
     9. Device Assembly 
     Once the sensor module  120  is installed in the channel  116  and connected to a master board, the controller  150 , and/or another component inside the frame  110  (e.g., via a flexible PCB, as shown in  FIGS.  2 B and  9 B ), the display  182  can be installed on the front side of the frame  110  such that edges of the display  182  extend up to (or near) the perimeter of the frame  110  and enclose the channel  116 . For example, the perimeter of the display  182  can be bonded to and/or sealed against the perimeter of the frame  110 —that is, along the lateral frame structure  114  and outside of the channel  116 . In particular, the display  182  can be bonded to the frame  110  along the narrow (e.g., one-millimeter-wide) section of the frame  110  between the channel  116  and the front edge of the first side of the frame  110 . Furthermore, in this example, the adhesive or seal that bonds the perimeter of the display  182  to the frame  110  can exhibit compliance in shear in order to: absorb inward deflection of the lateral frame structure  114  when depressed by a user; and limit transfer of this deflection into the edge display, which may otherwise distort an image rendered by the display  182 . 
     A rear cover panel  174  can be similarly bonded to the frame  110  along the narrow (e.g., one-millimeter-wide) lateral frame structure  114  of the frame  110  and can enclose slots between bridges along the base of the channel  116 . Thus, the display  182  and the rear cover panel  174  can cooperate to enclose the channel  116  and the sensor module  120 , and the channel  116  and the sensor module  120  can fall within a waterproof or water-resistant envelope formed by the frame  110 , the display  182 , and the rear cover panel  174 . 
     10. Input Detection 
     Therefore, each sensor, in the linear array of sensors  124  in the sensor module  120 , can: face a section of the lateral frame structure  114 ; and output a sense signal representing local deflection of this section of the lateral frame structure  114 . Accordingly, during a scan cycle, the controller  150  can: read a set of sense signals from the linear array of sensors  124 ; interpret a set of forces applied to sections of the lateral frame structure  114  during the scan cycle based on the set of sense signals; interpolate a particular position of a side input—applied to the mobile computing device proximal the first edge of the display  182  during the scan cycle—based on the set of forces and known positions of these sensors along the channel  116 ; estimate a total force magnitude of the side input based on a combination of the set of forces; and output the particular position and the force magnitude of the side input, such as to a processor or master controller  150  in the device  170 . The controller  150  can also: repeat this process for subsequent scan cycles, such as at a rate of 100 Hz, to detect locations and force magnitudes of side inputs on the device  170  during these subsequent scan cycles; implement input tracking techniques to track side inputs on the device  170  over multiple consecutive scan cycles; and/or detect changes in force magnitudes of individual side inputs; etc. 
     In one implementation, during operation, the controller  150 : reads a set of resistance values across each drive and sense electrode pair  125  in the sensor module  120 ; transforms these resistance values into a set of force magnitudes, such as based on a stored force-resistance model, scaling function, or lookup table; interpolates between these force magnitudes based on known locations of these sensors in the channel  116 ; stores these measured and interpolated forces magnitudes in a force gradient that represents the side of the device  170 ; and detects a set of contiguous regions in the force gradient that exhibit force magnitudes greater than a threshold force. Then, for each of these regions in the force gradient, the controller  150 : calculates a total force magnitude of a side input in this region based on a combination (e.g., a sum) of force magnitudes represented in this region of the force gradient; calculates a centroid of this region of the force gradient; and returns (e.g., to a processor in the device  170 ) a side input at a location of the centroid and of the total force magnitude. 
     10.1 Input Characterization 
     The controller  150  can also characterize a side input as: a finger (or an intended input) if the length of the corresponding region of the force gradient is less than a threshold finger length (e.g., 12 millimeters); a thumb if the length of the corresponding region of the force gradient is within a thumb length range (e.g., 12 to 20 millimeters); or a palm if the length of the corresponding region of the force gradient is greater than a threshold palm length (e.g., 12 to 20 millimeters). Additionally or alternatively, the controller  150  can characterize a side input as: a finger (or an intended input) if the peak applied force (or peak applied pressure) within a region of the force gradient associated with this side input exceeds a threshold peak finger force (e.g., 100 grams); a thumb if the peak applied force within a region of the force gradient associated with this side input falls within a thumb force range (e.g., between 25 and 100 grams); or a palm if the peak applied force within a region of the force gradient associated with this side input falls below a threshold peak palm force (e.g., less than 25 grams). 
     Additionally or alternatively, the controller  150  can isolate a singular side input—in a group of concurrent side inputs into the device  170 —most likely to represent an intention selection at the device  170 . For example, the controller  150  can identify a particular side input—within a group of concurrent side inputs—at an intentional selection input in response to the particular side input exhibiting greatest peak force or greatest pressure (i.e., total force magnitude divided by total area or length of the input) within the group of side inputs. The controller  150  can then implement methods and techniques described above and below to characterize the particular side input and to return characteristics of the particular side input (e.g., location and/or total force magnitude) to a processor or other subsystem  100  within the device  170 . 
     10.2 Resolution 
     As shown in  FIG.  2 B , the sensor module  120  can include drive and sense electrode pairs  125  arranged in a small number of (e.g., one, two) columns and a large number of (e.g., 24, 32) rows. Accordingly, the sensor module  120  can exhibit low resolution to side inputs along the depth of the side of the device  170  and high(er) resolution along the length of the side of the device  170 . 
     In one implementation, the channel  116  and the linear array of sensors  124  extend longitudinally over lengths greater than 80% of the longitudinal length of the first side of the mobile computing device. In this example, the controller  150  can detect locations and force magnitudes of side inputs—within a row of discrete regions on the first side of the mobile computing device—based on sense signals output by the linear array of sensors  124 , wherein each discrete region in the row of discrete regions on the first side of the mobile computing device defines a longitudinal length less than 10% of the longitudinal length of the first side of the mobile computing device. For example, a first side  171  of the device  170  can define a length of 150 millimeters; the channel  116  can extend over a length of 140 millimeters along the first side  171  of the device  170 ; and the sensor module  120  can define a length of 138 millimeters and include 32 drive and sense electrode pairs  125  at a pitch distance of 4.25 millimeters. Accordingly, the controller  150  can detect side inputs at 32 discrete sensible regions along the length of the side of the device  170 . The controller  150  can also interpolate forces between these 32 discrete sensible regions (e.g., at one position between adjacent sensible regions) in order to up-sample sense signals read from the sensor module  120 . 
     10.3 Input Tracking and Gesture Interpretation 
     The controller  150  can also repeat the foregoing process(es) during subsequent scan cycles and interpret particular types of side inputs and/or side input gestures based on side inputs detected over multiple scan cycles. 
     For example, the controller  150  can characterize a side input as an “intended selection” (or “button press”) in response to detecting: a large increase in force magnitude applied at a particular location on the side of the device  170 —adjacent a virtual button  188  rendered on the display  182 —over a first subset of scan cycles while force magnitudes of side input at other locations on the device  170  remain constant or increase slightly; immediately followed by a decrease in force magnitude applied to the particular location on the side of the device  170  or release of the side input from the particular location over a subsequent sequence of scan cycles. The controller  150  (or a processor in the device  170 ) can then trigger an action linked to the virtual button  188 . 
     In a similar example, the controller  150  can: implement methods and techniques described above to detect locations and total force magnitudes of individual side inputs on sides of the device  170 ; and convert these total forces to average pressures based on the total areas (or lengths) of the corresponding side input. In this example, the controller  150  can then characterize a side input as an “intended selection” in response to detecting: a large increase in pressure applied at a particular location on the side of the device  170 —adjacent a virtual button  188  rendered on the display  182 —over a first subset of scan cycles while pressures of side input at other locations on the device  170  remain constant or increase slightly; immediately followed by a decrease in pressure applied to the particular location on the side of the device  170  or release of the side input from the particular location over a subsequent sequence of scan cycles. The controller  150  (or a processor in the device  170 ) can then trigger an action linked to the virtual button  188 . 
     In a similar example, the controller  150  can: characterize a side input as an “intended selection” in response to detecting: a large increase in peak applied force (or peak pressure, rather than total force or total pressure) within a particular region of a side input on the side of the device  170  over a first subset of scan cycles while peak applied forces within regions of other side inputs on the side of the device  170  remain constant or increase slightly; immediately followed by a decrease in peak applied force within the particular region over a subsequent sequence of scan cycles. 
     In another example, the controller  150  can characterize a group of concurrent side inputs as a “squeeze” gesture in response to detecting: an increase in force magnitude applied to a large contiguous area on a first side  171  of the device  170  (e.g., a thumb or palm input); comparable increases in force magnitudes applied to a group of (e.g., three, four) contiguous discrete areas on the opposing side of the device  170  (e.g., three or four fingers); followed by similar and concurrent decreases in force magnitudes of all side inputs in this group. 
     In yet another example, the sensor module  120  can characterize a side input as a “swipe” or “scroll” gesture in response to detecting: an increase in force magnitude applied to a first location on a side of the device  170  over a first sequence of scan cycles; followed by transition of the side input at a similar force magnitude to a second location on the side of the device  170  over a subsequent sequence of scan cycles. Accordingly, the controller  150  can output a swipe or scroll command at a rate corresponding to the transition rate of the side input from the first location toward the second location. 
     10.4 Calibration 
     In one implementation, the controller  150  stores a set of baseline signal values representing contact resistance between the linear array of sensors  124  in the sensor module  120  and the force-sensitive layer  126  during absence of side inputs on the mobile computing device. Then, during a scan cycle, the controller  150 : reads a set of sense signals from the linear array of sensors  124 ; calculates a set of corrected sense signals based on the set of sense signals and the set of baseline signal values (e.g., by subtracting corresponding baseline signal values from these sense signals); interprets a set of nominal forces applied to sections of the lateral frame structure  114  during the scan cycle based on the set of corrected sense signals; and estimates total force magnitudes of side inputs on the mobile computing device—proximal the edge of the display  182  during the scan cycle—based on a combination of the set of corrected forces. 
     For example, in this implementation, the controller  150  can record (or “tare”) baseline electrical (e.g., voltage or resistance) values read from sensors in the sensor module  120  when no force is applied to the sides of the device  170  during a setup period. Then, during an operating period, the controller  150  can: correct or “normalize” sense signals read from drive and sense electrode pairs  125  in the sensor module  120  by subtracting these stored baseline electrical values from sense signals read from corresponding drive and sense electrode pairs  125 ; and convert these corrected sense signals to force values based on a stored force-resistance model, scaling function, or lookup table, etc. 
     Alternatively, in this implementation, the controller  150  can: record (or “tare”) baseline electrical (e.g., voltage or resistance) values read from sensors in the sensor module  120  when no force is applied to the sides of the device  170  during a setup period; convert these baseline electrical signals to baseline force values based on a stored force-resistance model, scaling function, or lookup table, etc.; and store these baseline force values. Then, during an operating period, the controller  150  can: read sense signals read from drive and sense electrode pairs  125  in the sensor module  120 ; convert these uncorrected sense signals to uncorrected force values based on the stored force-resistance model, scaling function, or lookup table, etc.; and then subtract the baseline force values from the uncorrected force values to calculate corrected force values along the side of the device  170 . 
     11. Contextual Inputs 
     The controller  150  (or a separate or master processor in the device  170 ) can also detect, interpret, and handle side inputs into the device  170  as a function of content rendered on the display  182  (e.g., locations of virtual buttons  188  rendered along the perimeter of the display  182 ) and/or screens or applications currently executing on the device  170 . 
     For example, while the display  182  renders a lock screen and/or a home screen, the controller  150  can: read sense signals from the sensor module  120 ; implement methods and techniques described above to detect groups of inputs on both sides of the device  170  and to interpret these inputs as a “squeeze” input; and then trigger the device  170  to transition to a “sleep” or “hibernate” mode responsive to this “squeeze” input. Similarly, while the display  182  is in the “sleep” or “hibernate” mode with the display  182  off, the controller  150  can: read sense signals from the sensor module  120 ; implement methods and techniques described above to detect groups of inputs on both sides of the device  170  and to interpret these inputs as a “squeeze” input; and then trigger the device  170  to transition to wake and render a lock screen responsive to this “squeeze” input. 
     In another example, while a camera application is open on the device  170 , the controller  150  can: implement methods and techniques described above to detect a group of side inputs on the sides of the device  170 ; and trigger a shutter function within the camera application in response to at least one of these side inputs spanning a total area or length less than a threshold selection dimension (e.g., a threshold finger area or length) and exhibiting a total force that exceeds a high threshold force (e.g., 165 grams) and then drops below a lower threshold force (e.g., 70 grams). Additionally or alternatively, in this example, the controller  150  can trigger a video capture or image burst function within the camera application in response to at least one of these side inputs spanning a total area or length less than the threshold selection dimension and exhibiting a total force that exceeds a high threshold force (e.g., 165 grams) for more than a threshold duration (e.g., one second). 
     In yet another example, while a social media application is executing on the device  170 , the controller  150  can: implement methods and techniques described above to detect a side input that exceeds a threshold peak force, force magnitude, or pressure; track this side input over multiple scan cycles; detect the side input—at an approximately consistent peak force, force magnitude, or pressure—transitioning downward along the side of the device  170 ; interpret this side input as a “downward scroll” input; and then trigger the social media application to scroll downwardly through a social feed at a rate proportional to the downward scroll input. Additionally or alternatively, in this example, the controller  150  can: implement methods and techniques described above to detect a group of inputs on two opposing sides of the device  170 ; interpret a squeeze (or “pinch”) gesture input in the device  170  in response to this group of input containing two opposing side inputs of similar sizes and similar force magnitudes exceeding a threshold force magnitude; and then trigger the social media application to scroll downwardly through a social feed at a rate responsive to this squeeze input and proportional to force magnitudes (e.g., the average or total force magnitudes) of these two opposing side inputs. 
     Therefore, the controller  150  (or other processor in the device  170 ) can map individual side inputs or groups of concurrent side inputs to different input types based on screens rendered or applications executing on the device  170 . 
     12. Dynamic Button Allocation 
     As shown in  FIGS.  5  and  6   , the device  170  can dynamically reassign regions of sides of the device  170  to different command functions, such as based on the current orientation of the device  170 , screens currently rendered on the device  170 , applications currently executing on the device  170 , and/or locations of side inputs detected at the device  170  during a current scan cycle. The device  170  can then render virtual buttons  188 —such as in the form of icons and/or text descriptions—of various command functions about the perimeter of the display  182  proximal regions of sides of the device  170  currently assigned to these command functions. 
     More specifically, based on the current orientation of the device  170 , screens currently rendered on the device  170 , applications currently executing on the device  170 , and/or locations of side inputs detected at the device  170  during a current scan cycle, the device  170  can dynamically: remap associations between regions along the sides of the device  170  and particular command functions; and update iconography rendered on the display  182  to reflect these new side input mappings. 
     12.1 Example 
     In one example shown in  FIG.  5   , while the device  170  display is off, displaying a lock screen, or displaying a home screen, the controller  150  (or other processor in the device  170 ) can: toggle the device  170  between sleep and locked-screen modes in response to brief side inputs (e.g., a “press” input exceeding a threshold force magnitude for less than two seconds) at a first region of the sensor module  120  (e.g., proximal an upper corner of the device  170 ); render a virtual “power” button on the display  182  adjacent this first region of the sensor module  120 ; increase or decrease an output volume of the device  170  in response to brief side inputs or “swipe” inputs within a second region of the sensor module  120  proximal a middle portion of the side of the device  170 ; render virtual “volume increase” and “volume decrease” buttons on the display  182  adjacent this second region of the sensor module  120 ; toggle audible notifications (e.g., inbound messages, alarms) in response to side inputs (e.g., a “squeeze” or “pinch” gesture) within a third region of the sensor module  120  proximal a lower portion of the side of the device  170  (e.g., lower half of the device  170 ); and render a virtual “silence” button on the display  182  adjacent this third region of the sensor module  120 . 
     Later, when a call is inbound to the device  170 , the controller  150  (or the processor, etc.) can: remove the virtual “power,” volume increase,” and “volume decrease” buttons from the display  182 ; remap the entire length—including the first, second, and third regions—of the sensor module  120  to detecting a “squeeze” input; render a virtual “squeeze to silence” indicator on the display  182 ; and then selectively silence the inbound call in response to detecting a “squeeze” or “pinch” side input at any position along the length of this sensor module  120 . 
     At a later time, when the user opens a camera application at the device  170  and holds the device  170  in a portrait orientation, the controller  150  (or other processor in the device  170 ) can automatically: remap the first region of the sensor module  120  to a camera “shutter” control; trigger the camera shutter in response to detecting a side input in the first region of the sensor module  120 ; remap the second region of the sensor module  120  to “zoom in” and “zoom out” controls; trigger the camera application to zoom a viewfinder in and out in response to detecting side inputs in the second region of the sensor module  120 ; remap a first subsection of the third region of the sensor module  120  to a “video capture” control; and trigger the camera to record a video in response to detecting a side input in this first subsection of the third region of the sensor module  120 ; and update the display  182  to render virtual buttons  188  to reflect these remapped controls. Furthermore, the controller  150  (or other processor in the device  170 ) can: assign a focus force threshold and a shutter force threshold—greater than the focus force threshold—to the first region of “shutter” control; trigger the camera shutter in response to detecting a side input of total force, peak force, or peak pressure exceeding the shutter force threshold in the first region of the sensor module  120 ; and trigger the camera application to refocus the camera in response to detecting a side input of total force, peak force, or peak pressure between the shutter and focus force thresholds in the first region of the sensor module  120 . Then, if the user rotates the device  170  to a landscape orientation while the camera application is open, the controller  150  (or other processor in the device  170 ) can automatically: remap the first region of the sensor module  120  to “zoom in” and “zoom out” controls; maintain the “video capture” control mapped to the first subsection of the third region of the sensor module  120 ; remap the camera “shutter” control to a second subsection of the third region of the sensor module  120  proximal an upper-right corner of the device  170  in the landscape orientation; and update the display  182  to render virtual buttons  188  to reflect these remapped controls. 
     12.2 Light Input Defines Virtual Button Location 
     Additionally and/or alternatively, the device  170  can dynamically remap command functions to different regions along the sensor module  120  based on locations of light (i.e., low-force, or “resting”) side inputs detected along the side of the device  170 . 
     In one implementation, the controller  150  (or other processor in the device  170 ): detects a first input of a first force magnitude and at a first location on the first side of the mobile computing device at a first time based on a first set of sense signals read from the array of sensors  124  during a first scan cycle; and triggers the display  182  to render a first virtual button  188  adjacent the first location during a first period of time succeeding the first scan cycle in response to detecting the first input at the first location. The controller  150  then: detects a second input of a second force magnitude and proximal the first location on the first side of the mobile computing device during the first period of time based on a second set of sense signals read from the array of sensors  124  during a second scan cycle succeeding the first scan cycle; and triggers an action affiliated with the first virtual button  188  in response to a) detecting the second input proximal the first location and b) the second force magnitude exceeding the first force magnitude. Later, the controller  150  can: detect a third input at a third location on the second side of the mobile computing device at a third time based on a third set of sense signals read from the second array of sensors  144  during a third scan cycle succeeding the second scan cycle; and trigger the display  182  to render the first virtual button  188  adjacent the third location on the second side  172  of the device  170  during a third period of time succeeding the third scan cycle in response to detecting the third input at the third location on the second side  172  of the device  170 . 
     In one example, during a scan cycle, the controller  150 : detects a set of (e.g., three, six) side inputs on the side of the device  170  based on sense signals read from a first sensor module  120  on a first side  171  of the device  170  and a second sensor module  140  on a second side  172  of the device  170 ; and identifies these side inputs as “resting” side inputs in response to their total force magnitudes, peak force magnitudes, or peak pressures exceeding a threshold force sensitive floor (e.g., 10 grams to filter and discard noise in the sensor module  120 ) and falling below a side input force threshold (e.g., 165 grams). Alternatively, the controller  150  can identify these side inputs as “resting” side inputs in response to their total force magnitudes, peak force magnitudes, or peak pressures differing by less than a threshold difference (e.g., +/−8%). The controller  150  (or other process in the device  170 ) can also identify a subset of these side inputs that correspond to individual fingers, such as side inputs characterized by lengths less than a threshold length (e.g., 20 millimeters). Alternatively, the controller  150  can: identify three or more side inputs on first side  171  of the device  170  as fingers with the topmost of these side inputs corresponding to an index finger; identify a largest side input on the second, opposing side of the device  170  as a palm; and identify a second side input on the second side  172  of the device  170  as a thumb. 
     The controller  150  can then: retrieve a prioritized list of command functions associated with a screen currently rendered on the display  182  or an application currently executing on the device  170 ; assign a first command function in the prioritized list to a first region of the first sensor module  120  adjacent a topmost side input identified as a finger; update the display  182  to render a first virtual button  188  for the first command function adjacent this first region of a first sensor module  120 ; assign a second command function in the prioritized list to a second region of the first sensor module  120  adjacent a second side input identified as a finger; update the display  182  to render a second virtual button  188  for the second command function adjacent this second region of the first sensor module  120 ; etc. The controller  150  can also: reassign a “screen lock” command function to a region of the second sensor module  140  adjacent side input identified as a thumb; and update the display  182  to render a virtual “screen lock” button adjacent this region of the second sensor module  140 . 
     The controller  150  (or other processor in the device  170 ) can then execute a particular command function in response to detecting a side input—that exceeds a threshold force magnitude (e.g., 165 grams)—in a particular region of the first or second sensor modules  140  currently mapped to this particular command function. The controller  150  can also regularly (e.g., continuously, once per two-second interval) repeat the foregoing process to dynamically reassign command functions to locations along sides of the device  170  adjacent resting side inputs as a user naturally holds the device  170  in her hand, thereby enabling the user to immediately access primary or high-priority functions at the device  170  without moving her fingers along the device  170  or repositioning the device  170  in her hand. 
     Therefore, the controller  150  (or other processor in the device  170 ) can dynamically reassign virtual buttons  188  to different locations along a sensor module  120  and dynamically adjust force thresholds for responding to side inputs at these locations. 
     12.3 Device Orientation Defines Virtual Button Location 
     In another implementation, the controller  150  can: detect a current orientation of the device  170  based on outputs of an accelerometer on the device  170 ; rotate a mapping between particular command functions and regions of the sensor module  120 ( s ) by 180° when the device  170  is inverted; and/or rotate a mapping between particular command functions and particular locations by 900 (for a device  170  with sensor modules  120  on all four sides) when the device  170  is transitioned between portrait and landscape orientations. 
     In a similar implementation in which the device  170  includes two sensor modules  120  on its left and right sides, the controller  150  can assign a first set of virtual buttons  188  to a lower region of the right sensor module  120 , a second set of virtual buttons  188  to an upper region of the right sensor module  120 , a third set of virtual buttons  188  to an upper region of the left sensor module  120 , and a fourth set of virtual buttons  188  to a lower region of the left sensor module  120  when the device  170  is held in the portrait orientation. When the device  170  is transitioned clockwise from the portrait orientation into the landscape orientation, the controller  150  can dynamically reassign the first set of virtual buttons  188  to the lower region of the left sensor module  120 , the second set of virtual buttons  188  to the lower region of the right sensor module  120 , the third set of virtual buttons  188  to the upper region of the right sensor module  120 , and the fourth set of virtual buttons  188  to a upper region of the left sensor module  120 . Similarly, when the device  170  is transitioned counter-clockwise from the portrait orientation into the landscape orientation, the controller  150  can dynamically reassign the first set of virtual buttons  188  to the upper region of the right sensor module  120 , the second set of virtual buttons  188  to the upper region of the left sensor module  120 , the third set of virtual buttons  188  to the lower region of the left sensor module  120 , and the fourth set of virtual buttons  188  to a lower region of the right sensor module  120  such that the virtual buttons  188  remain in approximately the same quadrants of the device  170  relative to gravity or a ground plane regardless of orientation of the device  170 . 
     12.4 Handedness 
     In a similar implementation, the controller  150  can implement methods and techniques described above to detect: a palm and/or a thumb on a first side  171  of the device  170  based on a first set of sense signals read from a first sensor module  120  on this first side  171  of the device  170 ; and a set of fingers on a second side  172  of the device  170  based on a second set of sense signals read from a second sensor module  140  on this second side  172  of the device  170 . The device  170  can then: detect a handedness of a hand holding the device  170  based on positions of the palm, thumb, and/or fingers on sides of the device  170 ; and selectively reverse (e.g., mirrors) a mapping between command functions and regions of these sensor modules  120  based on the handedness of the hand such that a user&#39;s thumb and index finger, etc. can always reach the same virtual buttons  188  (given a particular screen rendered on the display  182  or application executing on the device  170 ) regardless of whether the user is holding the device  170  with her left hand or right hand.
 
13. Continuous Input Region+Discrete Button
 
     In one variation shown in  FIG.  4   , the lateral frame structure  114  of the frame  110  defines a bore  164  (e.g., a round or square hole) extending laterally between the first side of the mobile computing device and the channel  116 ; and the system  100  further includes a physical button element  162  arranged in the bore  164 , accessible from the first side of the mobile computing device, and configured to selectively compress a particular region of the force-sensitive layer  126  adjacent a particular sensor in the sensor module  120 . In this variation, the wherein the controller  150  can therefore: implement methods and techniques described above to detect locations and force magnitudes of side inputs on the mobile computing device—proximal the first edge of the display  182  and offset from the physical button element  162 —based on sense signals output by sensors in the linear array of sensors  124  other than the particular sensor; and detect force magnitudes of inputs on the physical button element  162  based on sense signals output by the particular sensor. 
     Generally, in this variation, the sensor module  120 : can define a singular, continuous substrate  121  and singular, continuous force-sensitive layer  126  arranged in the channel  116  along a side of the device  170 ; can output sense signals representing inward deflection of the lateral frame structure  114  responsive to inputs along the side of the device  170 ; and can also output sense signals representing location compression of the force-sensitive layer  126  responsive to depression of a physical button passing laterally through the lateral frame structure  114 . For example, the sensor module  120  can be sealed (e.g., waterproofed) against the channel  116  and can detect inputs along the first side  171  of the device  170 —from both deflection of the lateral frame structure  114  and depression of the physical button—without additional discrete buttons or seals around these discrete buttons. 
     14. Sensor Module and Touchscreen Fusion 
     In one variation in which the device  170  includes a touchscreen  180 , the controller  150  (or other processor in the device  170 ) can: read sense signals from the touchscreen  180  and interpret high-resolution lateral and longitudinal locations on inputs on the touchscreen  180  during a scan cycle based on the sense signals (or access a touch image output by a second controller  150  in the device  170  based on sense signals read from the touchscreen  180 ); read sense signals from the sensor module  120  arranged along a first side  171  of the device  170  and interpret total force magnitudes (or peak force magnitudes, peak pressures) and low-resolution locations of side inputs along the side of the device  170  during the scan cycle based on sense signals read from the sensor module  120 ; and identify a touch input detected by the touchscreen  180  as corresponding to a side input detected by the sensor module  120  if the locations of these inputs are within a threshold distance (e.g., if a centroid of the touch input is within 3 millimeters of the edge of the touchscreen  180  on the first side  171  of the device  170 ). Then upon identifying the touch and side inputs as the same input, the controller  150  can: fuse the high-resolution position of the touch input and the total force magnitude (or peak force magnitude, peak pressure) of the side input into a high-resolution side input; and output this side input (e.g., to another processor in the device  170 ) during the scan cycle. 
     More specifically, the touchscreen  180  can include a relatively high density of drive and sense electrode pairs  125  (e.g., one sensor or drive channel  116  per millimeter of length), and the sensor module  120  can include a relatively low density of drive and sense electrode pairs  125  (e.g., one sensor or drive channel  116  per 4.5 millimeters of length). Therefore, the touchscreen  180  can exhibit relatively high spatial resolution, and the sensor module  120  can exhibit relatively low spatial resolution. Thus, in this variation, the controller  150  (or other processor in the device  170 ) can link a touch input detected at the high-resolution touchscreen  180  and a side input detected at the force-sensitive sensor module  120  during a scan cycle if: the lateral (or “x”) position of (the centroid of center of) the touch input falls along the edge of the screen adjacent the sensor module  120  (e.g., within a lateral threshold distance of 3 millimeters from the edge of the touchscreen  180 ); and the longitudinal (or “y_touch”) position of the touch input falls within a threshold longitudinal distance of the longitudinal (or “y_side”) position of the side input (e.g., within a longitudinal threshold distance of the pitch distance between sensors in the sensor module  120 , or 4.5 millimeters). Then, upon linking these touch and side inputs, the controller  150  can fuse the high-resolution longitudinal position of the touch input detected by the touchscreen  180  and the total force magnitude (or peak force magnitude, peak pressure) of the side input detected by the sensor module  120  into a side input of high(er) spatial resolution. 
     For example, the touchscreen  180  can include: the display  182 ; and a touch sensor arranged across the display  182  and configured to output sense signals representing locations of touch inputs over the display  182 . In this example, the controller  150  can: read a first set of sense signals from the touch sensor during a scan cycle; detect a first lateral location and a first longitudinal location of a first touch input over the display  182  during the scan cycle based on the first set of sense signals; read a second set of sense signals from the array of sensors  124  in the sensor module  120  during the scan cycle; interpret a first force magnitude of a side input in a first region of a first side of the mobile computing device based on the second set of sense signals; and, in response to the first lateral location of the first touch input falling within a threshold distance of the first region of a first side of the mobile computing device, output a representation of the first side input of the first force magnitude and at the first longitudinal location on the first side of the mobile computing device during the scan cycle. 
     15. Variation: Curved Display with Exposed Frame 
     In one variation shown in  FIG.  7   , the display  182  includes: a planar display section  184  that defines the front face of the mobile computing device; and a non-planar (e.g., curved) display section that extends around a first side of the mobile computing device and defines the first edge of the display  182 . In this variation, the lateral frame structure  114  of the device  170  can extend along and behind the non-planar display section  186 , and the non-planar display section  186  can extend over and enclose the sensor module  120  in the channel  116 . For example, the lateral frame structure  114  can: define a display  182  seat extending along, bonded to, and/or sealed against the first edge of the display  182 ; and extend past the first edge of the display  182  to define the first side  171  of the device  170 . Accordingly, the seat of the lateral frame structure  114  can form a thin (e.g., 0.025″) gap along the first edge of the display  182 , and the lateral frame structure  114  can deflect inwardly to close this gap and locally compress the force-sensitive layer  126  against sensors in the sensor module  120  responsive to forces applied along the first side  171  of the device  170 . Therefore, in this variation, the lateral frame structure  114  can deflect inwardly to locally compress the force-sensitive layer  126  with minimal or no deflection of the first edge of the display  182 . 
     In one example shown in  FIG.  7   , the frame  110  includes: a first curved (or “radiused”) side; a channel  116  and bridges inset from and extending parallel to the first curved side; a front ridge extending along the front of the frame  110  between the channel  116  and the first curved side; and a rear ridge extending along the rear of the frame  110  between the channel  116  and the first curved side. As described above, a sensor module  120  can be loaded into this channel  116 . In this example, the device  170  includes: a display  182  (and front cover panel) with a curved “waterfall” edge extending over the front of the frame  110  and the first curved side of the frame  110  and terminating at the front ridge; and a (rigid) rear cover panel  174  with a curved “waterfall” edge extending over the rear of the frame  110  and the first curved side of the frame  110  and terminating at the rear ridge. In particular, the edges of the display  182  (and/or front cover panel) and the rear cover panel  174  can be bonded to the frame  110  adjacent the front and rear ridges, respectively, (e.g., with a flexible waterproof adhesive) with a center section of the first curved side of the frame  110  remaining exposed. Thus, the free edges of the display  182  (and/or front cover panel) and the rear cover panel  174  adjacent the channel  116  can deflect responsive to an applied force on the first side  171  of the device  170  and transfer a portion of this force into the curved side of the frame  110 , which also deflects and transfers a portion of this force into an adjacent segment of the sensor module  120 . Furthermore, the display  182  (and/or front cover panel) and rear cover panel  174  can be bonded and/or sealed against the perimeter of the frame  110 —beyond the channel  116  and the sensor module  120 —such that the channel  116  and the sensor module  120  fall within the waterproof or water-resistant envelope formed by the frame  110 , the display  182 , and the rear cover panel  174 . 
     16. Variation: Curved Display with Concealed Frame 
     In a similar variation shown in  FIG.  8   , the channel  116  can extend forward from a rear of the frame  110  toward the display  182 ; and the non-planar display section  186  can extend around the frame  110  to conceal the lateral frame structure  114  and can define the first side  171  of the device  170  bonded along and/or sealed against the later frame structure. In this variation, the rear cover panel  174  can: similarly extend around the frame  110  to conceal the lateral frame structure  114 ; abut the first edge of the display  182 ; and enclose the sensor module  120  in the channel  116 . Therefore, in this variation, the first edge of the display  182  can deflect inwardly to communicate the force of a side input into the lateral frame structure  114 , which then deflects inwardly to locally compress the force-sensitive layer  126 . 
     In one example shown in  FIG.  8   , the device  170  includes: a frame  110  with a first curved (or “radiused”) side; a display  182  (and a front cover panel) with a curved “waterfall” edge extending over a front of the frame  110  and the first curved side of the frame  110 ; and a (rigid) rear cover panel  174  that extends across the rear of the frame  110  and up to the perimeter of the display  182  to enclose and fully obscure the frame  110 . As described above, the frame  110  can also include a channel  116  and bridges along the first curved side of the frame  110 , and a sensor module  120  can be loaded into this channel  116 . In this example, the rear edge of the display  182  (and/or front cover panel) can be bonded to the first curved side of the panel (e.g., with a flexible waterproof adhesive) adjacent the channel  116  and sensor module  120 . Thus, the free edge of the display  182  (and/or front cover panel) adjacent the channel  116  can deflect responsive to an applied force on the first side  171  of the device  170  and transfer a portion of this force into the curved side of the frame  110 , which also deflects and transfers a portion of this force into an adjacent segment of the sensor module  120 . 
     17. Variation: Curved Display Defining Channel 
     In another variation in which the display  182  includes a non-planar display section  186  that wraps around an edge of the device  170 , the non-planar display section  186  and the frame  110  can cooperate to define the channel  116  and the sensor module  120  can be arranged (e.g., laminated) behind the non-planar display section  186 , as shown in  FIGS.  9 A and  9 B . 
     In one implementation shown in  FIGS.  9 B and  10   : the frame  110  defines a seat extending along its first edge and configured to receive a support base  129  (e.g., a “stiffening element”); and the support base  129  is contoured (e.g., molded, machined) to locate the sensor module  120  parallel to a plane that tangent to a line—centered over the sensor module  120 —extending along the non-planar display. During assembly, the sensor module  120 —including the force-sensitive layer  126  laminated across the substrate  121 —is arranged across and/or bonded to a support base  129 , which is then loaded onto the seat. A compression element  128  is installed over the sensor module  120  opposite the support base  129 , and the display  182  is then installed onto the frame  110  to enclose the sensor module  120  and compress the compression element  128  between the interior face of the non-planar display section  186  and the sensor module  120 , which is rigidly supported on the frame  110  via the support base  129 . In this implementation, the frame  110  can also define a lip: extending along the first edge of the display  182  (i.e., along the edge of the non-planar display section  186 ); and bonded and/or sealed to the first edge of the display  182 . For example, the lip can bonded to and/or sealed against the first edge of the display  182  with an adhesive or sealant exhibiting a low modulus of elasticity and that compresses and/or shears to enable the first edge of the display  182  to locally deflect inwardly toward the sensor module  120  and to thus compress the force-sensitive layer  126  responsive to side inputs along the first edge of the display  182 . 
     18. Variation: Capacitive Sensors 
     In one variation shown in  FIG.  12   , rather than a force-sensitive layer  126  and sensors configured to detect contact resistance across adjacent regions of the force-sensitive layer  126 , the sensor module  120  includes an array of drive and sense electrode pairs  125  arranged in a mutual capacitance configuration and configured to capacitively to a capacitance element along the adjacent side of the device  170 . Accordingly, in this variation, the controller  150  is configured to: read capacitance values (e.g., charge time, discharge time, voltage, resonant frequency) from the array of drive and sense electrode pairs  125 ; and convert these capacitance values into force magnitudes of side inputs adjacent these drive and sense electrode pairs  125 . 
     More specifically, in this variation, a side input applied to the side of the device  170  adjacent a particular drive and sense electrode pair  125  in the sensor module  120  can cause inward deflection of the side of the device  170 , which brings the adjacent region of the capacitance element closer to this particular drive and sense electrode pair  125  and changes the capacitance value (e.g., increases charge time, decreases discharge time, decreases voltage) read from the particular drive and sense electrode pair  125 . The controller  150  can then read this capacitance value, calculate a difference between this capacitance value and a baseline capacitance value (e.g., recorded when no side input is present on the device  170 ), and transform this capacitance value into a force magnitude of the side input proximal the particular drive and sense electrode pair  125 . The controller  150  can also: execute this process in series or in parallel for each other drive and sense electrode pair  125  in the sensor module  120  to calculate a force magnitude applied to the side of the device  170  during a scan cycle; interpolate force magnitudes between these drive and sense electrode pairs  125 ; assemble these measured and/or interpolated force magnitudes into a force gradient; and detect locations and total force magnitudes, peak forces, and/or peak pressures of side inputs along the device  170  during this scan cycle, as described above. 
     In one implementation: the display  182  includes a non-planar display section  186  that wraps around the side of the frame  110  adjacent the sensor module  120  to form all or a portion of a side of the device  170 ; and the capacitance element includes a conductive trace integrated into and extending near an edge of this non-planar display section  186  such that a force applied to the side of the device  170  inwardly deflects a local region of the edge of the non-planar display section  186 , which brings a local section of the conductive trace closer to an adjacent drive and sense electrode pair  125  and thus effects the capacitance of this drive and sense electrode pair  125 . 
     In this implementation, because the non-planar display section  186  is configured to deflect responsive to side inputs into the device  170 , because images rendered on the non-planar display section  186  may distort as the display  182  deflects, and/or because the non-planar display section  186  may be sensitive to fatigue and failure as a function of strain, the non-planar display section  186  (and the front edge of the lateral frame structure  114 ) can be configured to locally deflect inwardly toward the base structure  112  of the frame  110  by a small distance per unit force applied to the side of the device  170 , such as by a distance less than 0.0005 inch per pound of force applied to a local section of the side of the device  170 . More specifically, because the non-planar display section  186  may be sensitive to local deflection: the lateral frame  110  section can support the edge of the non-planar display section  186  and/or the display  182  can include a rigid (e.g., glass) cover layer configured to support the non-planar display section  186  against inward deflection; and the drive and sense electrode pairs  125  can be tuned to exhibit high sensitivity to small deflections in the adjacent edge of the non-planar display section  186 , thereby enabling the controller  150  to detect and interpret side inputs along the non-planar display section  186  despite small deflections of non-planar display section  186  responsive to these side inputs. 
     In a similar implementation shown in  FIG.  12    in which the lateral frame structure  114  is non-metallic, the system  100  includes a compressive element (e.g., a foam strip) arranged between the sensor module  120  and the side of the device  170 , such as: between the sensor module  120  and the lateral frame structure  114  for the device  170  in which the lateral frame structure  114  defines the side of the device  170 ; or between the sensor module  120  and the non-planar display section  186  for the device  170  in which the display  182  wraps around the side of the device  170 . In this example, the capacitance element can include a conductive foil (e.g., an aluminum foil) arranged between the compressive element and the side of the device  170  such that a force applied to this side of the device  170  locally inwardly deflects the lateral frame structure  114  and/or the non-planar display section  186 , which locally compresses the compression element  128 , brings a local section of the conductive foil closer to an adjacent drive and sense electrode pair  125 , and thus effects the capacitance of this drive and sense electrode pair  125 . 
     In another implementation, the frame  110  includes the lateral frame structure  114 , which: extends along and adjacent a first edge of the display  182 ; is supported on a first side of the base structure  112  of the frame  110 ; cooperates with the base structure  112  to define a channel  116  arranged behind the display  182  and extending longitudinally between the lateral frame structure  114  and the first side of the base structure  112 ; and is configured to locally deflect inwardly toward the base structure  112  responsive to forces applied to the side of the mobile computing device adjacent an edge of the display  182 . In this implementation, the sensor module  120  is arranged within the channel  116  along the base structure  112  and offset from an inner face of the lateral frame structure  114  (e.g., by 0.5 millimeter). Furthermore, in this implementation, the frame  110 —and therefore the lateral frame structure  114 —can include a metallic or conductive material, such as: cast, forged, sintered, or billet aluminum or steel; or co-molded polymer and conductive particulate. Therefore, each sensor (e.g., each drive and sense electrode pair  125 ) in the linear array of sensors  124  can: capacitively couple to an adjacent section of the lateral frame structure  114 ; and output a sense signal representing a distance to this adjacent section of the lateral frame structure  114 —and therefore representing inward deflection of the adjacent section of the lateral frame structure  114  toward the sensor. More specifically, in this implementation, each sensor in the linear array of sensors  124  can: exhibit capacitive coupling to an adjacent section of the lateral frame structure  114  proportional to inward deflection of the adjacent section of the lateral frame  110 ; and output a sense signal representing capacitive coupling to the adjacent section of the lateral frame structure  114 . 
     In this variation, the controller  150  can store a set of baseline capacitance values representing nominal distances between the linear array of sensors  124  and adjacent sections of the lateral frame structure  114 . Then, during a scan cycle, the controller  150  can: read a set of sense signals from the linear array of sensors  124 ; calculate a set of corrected sense signals based on the set of sense signals and the set of baseline capacitance values; interpret a set of nominal forces applied to sections of the lateral frame structure  114  during the scan cycle based on the set of corrected sense signals; and estimate a total force magnitude of a side input on the mobile computing device, proximal the first edge of the display  182  during the scan cycle, based on a combination of the set of corrected forces. 
     Furthermore, in this variation, rather than drive and sense electrode pairs  125  arranged in a mutual capacitance configuration on one side of the substrate  110 , the sensor module  120  can: include an array of individual sense electrodes arranged in a self-capacitance configuration across the first side of the substrate  110 ; and a common ground electrode or individual ground electrodes arranged along the second side of the substrate opposite these sense electrodes. Accordingly, the controller  150  can implement similar methods and techniques to: detect changes in positions of local regions of the side of the device  170  relative to these sense electrodes based on capacitance values read from these sense electrodes; and then interpret force magnitudes and locations of side inputs on the device  170  based on these positional changes. 
     The systems and methods described herein can be embodied and/or implemented at least in part as a machine configured to receive a computer-readable medium storing computer-readable instructions. The instructions can be executed by computer-executable components integrated with the application, applet, host, server, network, website, communication service, communication interface, hardware/firmware/software elements of a user computer or device, wristband, smartphone, or any suitable combination thereof. Other systems and methods of the embodiment can be embodied and/or implemented at least in part as a machine configured to receive a computer-readable medium storing computer-readable instructions. The instructions can be executed by computer-executable components integrated by computer-executable components integrated with apparatuses and networks of the type described above. The computer-readable medium can be stored on any suitable computer readable media such as RAMs, ROMs, flash memory, EEPROMs, optical devices (CD or DVD), hard drives, floppy drives, or any suitable device. The computer-executable component can be a processor but any suitable dedicated hardware device can (alternatively or additionally) execute the instructions. 
     As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the embodiments of the invention without departing from the scope of this invention as defined in the following claims.