PATENT DOCUMENT

Publication Number: US-11540599-B1
Application Number: US-202016830088-A
Country: US
Kind Code: B1

Title: Watch band with adjustable fit

Abstract:
Watch bands can be provided with an ability to dynamically adjust the fit of a watch against a wrist of a user. One or more of a variety of tensioning elements can be provided with a shape memory polymer that responds to a stimulus to adjust a fit of the band. Such stimulus can be from user or actively applied by the watch. The shape memory polymer can be a composite material that provides high durability under cyclic stretching and high speed response of shape recovering while avoiding a drastic moduli drop by shape recovering.

Claims:
What is claimed is: 
     
       1. A watch band comprising:
 a cover defining ends configured to engage a housing of a watch; 
 a tensioning element between the ends of the cover, the tensioning element comprising a shape memory polymer and being configured to transition, based on an induced temperature, between:
 a first configuration in which the tensioning element is substantially straight; and 
 a second configuration in which the tensioning element is substantially serpentine. 
 
 
     
     
       2. The watch band of  claim 1 , wherein:
 the tensioning element is a first tensioning element; and 
 the watch band further comprises a second tensioning element that, while in the first configuration, is parallel to the first tensioning element. 
 
     
     
       3. The watch band of  claim 1 , wherein the tensioning element is configured to adjust a fit of the watch band in response to heat emitted from a wrist of a user when the watch band is worn on the wrist. 
     
     
       4. The watch band of  claim 1 , wherein the tensioning element is configured to respond to a stimulus to adjust at least one of a fastening force, a coiling force, and a pressure of the watch band on a wrist of a user. 
     
     
       5. The watch band of  claim 1 , wherein the shape memory polymer is a composite comprising a Tm-type shape memory polymer and a Tg-type shape memory polymer. 
     
     
       6. A watch band comprising:
 a watch engagement element configured to engage a housing of a watch; and 
 tensioning elements each comprising multiple tensioning layers overlapping each other and extending from the watch engagement element, each one of the tensioning layers extending a different distance from the watch engagement element, the tensioning layers comprising one or more shape memory polymers. 
 
     
     
       7. The watch band of  claim 6 , wherein the watch band defined an inner surface and an outer surface, wherein a shortest one of the tensioning layers is closer to the outer surface than any other one of the tensioning layers, and a longest one of the tensioning layers is closer to the inner surface than is any other one of the tensioning layers. 
     
     
       8. The watch band of  claim 6 , wherein each of the tensioning elements are configured to transition between:
 a first configuration in which the tensioning elements are a first distance away from each other; and 
 a second configuration in which the tensioning elements are a second distance away from each other. 
 
     
     
       9. The watch band of  claim 6 , wherein at least two of the tensioning layers have different thicknesses. 
     
     
       10. The watch band of  claim 6 , wherein at least two of the tensioning layers have different widths. 
     
     
       11. The watch band of  claim 6 , wherein the tensioning elements are configured to adjust a fit of the watch band in response to heat emitted from a wrist of a user when the watch band is worn on the wrist. 
     
     
       12. The watch band of  claim 6 , wherein the tensioning elements are configured to respond to a stimulus to adjust at least one of a fastening force, a coiling force, and a pressure of the watch band on a wrist of a user. 
     
     
       13. The watch band of  claim 6 , wherein the one or more shape memory polymers is a composite comprising a Tm-type shape memory polymer and a Tg-type shape memory polymer. 
     
     
       14. A watch band comprising:
 a watch engagement element configured to engage a housing of a watch; 
 a first tensioning layer connected to and extending from the watch engagement element, the first tensioning layer having a first terminal end that is a first distance away from the watch engagement element; 
 a second tensioning layer connected to and extending from the watch engagement element, the second tensioning layer having a second terminal end that is a second distance, greater than the first distance, away from the watch engagement element; and 
 a third tensioning layer connected to and extending from the watch engagement element, the third tensioning layer having a third terminal end that is a third distance, greater than the second distance, away from the watch engagement element. 
 
     
     
       15. The watch band of  claim 14 , wherein the watch band defined an inner surface and an outer surface, wherein the first tensioning layer is closer to the outer surface than are the second tensioning layer and the third tensioning layer, and the third tensioning layer is closer to the inner surface than are the first tensioning layer and the second tensioning layer. 
     
     
       16. The watch band of  claim 14 , wherein at least two of the first tensioning layer, the second tensioning layer, and the third tensioning layer have different thicknesses. 
     
     
       17. The watch band of  claim 14 , wherein at least two of the first tensioning layer, the second tensioning layer, and the third tensioning layer have different widths. 
     
     
       18. The watch band of  claim 14 , wherein the first tensioning layer, the second tensioning layer, and the third tensioning layer are configured to adjust a fit of the watch band in response to heat emitted from a wrist of a user when the watch band is worn on the wrist. 
     
     
       19. The watch band of  claim 14 , wherein the first tensioning layer, the second tensioning layer, and the third tensioning layer are configured to respond to a stimulus to adjust at least one of a fastening force, a coiling force, and a pressure of the watch band on a wrist of a user. 
     
     
       20. The watch band of  claim 14 , each of the first tensioning layer, the second tensioning layer, and the third tensioning layer comprises a composite of a Tm-type shape memory polymer and a Tg-type shape memory polymer.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 62/906,650, entitled “WATCH BAND WITH ADJUSTABLE FIT,” filed Sep. 26, 2019, the entirety of each of which is incorporated herein by reference. 
    
    
     FIELD 
     The present description relates generally to watch bands, and, more particularly, to watch bands with adjustable fit for a user&#39;s wrist. 
     BACKGROUND 
     Some electronic devices may be removably attached to a user. For example, a wristwatch or fitness/health tracking device can be attached to a user&#39;s wrist by joining free ends of a watch band together. 
     In many cases, watch bands may have limited fit adjustment increments available. For example, some bands have an incrementally user-adjustable size (e.g., a buckling clasp, pin and eyelet, etc.) whereas other bands have a substantially fixed size, adjustable only with specialized tools and/or expertise (e.g., folding clasp, deployment clasp, snap-fit clasp, etc.). Still other bands may be elasticated expansion-type bands that stretch to fit around a user&#39;s wrist. 
     In many cases, conventional watch bands may catch, pinch, or pull a user&#39;s hair or skin during use if the band is overly tight. In other cases, watch bands may slide along a user&#39;s wrist, turn about a user&#39;s wrist, or may be otherwise uncomfortable or bothersome to a user if the band is overly loose. These problems can be exacerbated during periods of heightened activity, such as while running or playing sports. Furthermore, adjusting the size or fit of conventional watch bands often requires multiple steps, specialized tools, and/or technical expertise. In other cases, sizing options available to a user may be insufficient to obtain a proper fit. In still further examples, the fit may be different and/or may be perceived to be different given certain environmental (e.g. temperature, humidity) or biological conditions (e.g., sweat, inflammation). As a result, users of conventional wristwatches and/or fitness/health tracking devices may select a tolerable (although not optimally comfortable) fit, reserving tight bands for fitness/health tracking devices and loose bands for conventional wristwatches. 
     However, some wearable electronic devices (such as smart watches) may be multi-purpose devices, providing in one example both fitness/health tracking and timekeeping functionality. Accordingly, a user may prefer the fit of a smart watch to vary with use. For example, a user may prefer a looser fit in a timekeeping mode and a tighter fit in a fitness/health tracking mode. 
     Accordingly, there may be a present need for systems and methods for dynamic adjustment of the fit of wearable electronic devices. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain features of the subject technology are set forth in the appended claims. However, for purpose of explanation, several embodiments of the subject technology are set forth in the following figures. 
         FIG.  1    illustrates a perspective view of a watch on a wrist of a user, according to some embodiments of the present disclosure. 
         FIG.  2    illustrates a side view of a watch with adjustable fit capabilities, according to some embodiments of the present disclosure. 
         FIG.  3    illustrates a side view of a watch with adjustable fit capabilities, according to some embodiments of the present disclosure. 
         FIG.  4    illustrates a side view of a watch with adjustable fit capabilities, according to some embodiments of the present disclosure. 
         FIG.  5    depicts a simplified block diagram of a watch, according to some embodiments of the present disclosure. 
         FIG.  6    illustrates a perspective view of a watch with an expanded view of a portion of a watch band, according to some embodiments of the present disclosure. 
         FIG.  7    illustrates a perspective view of a watch with a watch band in a loose configuration, according to some embodiments of the present disclosure. 
         FIG.  8    illustrates a perspective view of the watch of  FIG.  7    with the watch band in a tight configuration, according to some embodiments of the present disclosure. 
         FIG.  9    illustrates a perspective view of a watch with a watch band in a loose configuration, according to some embodiments of the present disclosure. 
         FIG.  10    illustrates a perspective view of a portion of the watch of  FIG.  9   , according to some embodiments of the present disclosure. 
         FIG.  11    illustrates a perspective view of a watch with a watch band in a loose configuration, according to some embodiments of the present disclosure. 
         FIG.  12    illustrates a perspective view of a portion of the watch of  FIG.  11   , according to some embodiments of the present disclosure. 
         FIG.  13    illustrates a sectional view of a watch band of the watch of  FIG.  12   , according to some embodiments of the present disclosure. 
         FIG.  14    illustrates a sectional view of a watch band of a watch, according to some embodiments of the present disclosure. 
         FIG.  15    illustrates a perspective view of a watch band of a watch, according to some embodiments of the present disclosure. 
         FIG.  16    illustrates a graph showing a comparison of watch band displacements for given loads, according to some embodiments of the present disclosure. 
         FIG.  17    illustrates a graph showing a comparison of watch band elongation for given loads, according to some embodiments of the present disclosure. 
         FIG.  18    illustrates a graph showing a comparison of watch band volume fractions for given elasticities, according to some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. 
     Embodiments described herein relate to systems and methods for dynamic adjustment of the fit of wearable electronic devices. It should be appreciated that the various embodiments described herein, as well as functionality, operation, components, and capabilities thereof may be combined with other elements, embodiments, structures and the like, and so any physical, functional, or operational discussion of any element or feature is not intended to be limited solely to a particular embodiment to the exclusion of others. 
     As noted above, many portable electronic devices may be removably attached to a user. In some examples, a heart rate sensor may be attached to a user&#39;s chest by a strap. In another example, a smart watch or a fitness device can be attached to a user&#39;s wrist by donning the watch with a watch band and/or joining free ends of a conventional watch band together. In other examples, a clasp or an elasticated band may optionally be used to secure the watch. In another example, a portable audio player may be secured to a user&#39;s arm by inserting the player into an armband case. 
     Although many embodiments are described herein with reference to wrist bands for attaching a wrist-worn electronic device to a user, one may appreciate that other form factors may be favored in other embodiments. In other words, the methods, systems, and techniques described herein with illustrative reference to wrist-worn devices may be equally applied to non-wrist worn devices. For example, in other embodiments, devices may be configured to attach to other limbs or body portions (e.g., necklaces, arm bands, waistbands, ear hooks, finger rings, anklets, toe rings, chest wraps, head bands, etc.). Furthermore, other embodiments described herein may be applied to dynamically adjust the fit of an electronic device to a non-user object such as a charging stand or station. In other embodiments, an electronic device can be fit to another biological subject such as an animal (e.g., pet collar). 
     As noted above, many conventional watch bands may be uncomfortable, painful, or bothersome if improperly fit to a user. For example, a user&#39;s skin and/or hair may be pinched or pulled if a conventional watch band is improperly fit. In another example, a user may be irritated by a watch that slides up and down a user&#39;s wrist and/or rotates about the user&#39;s wrist during use. 
     In other cases, the fit of a conventional watch band may be different and/or may be perceived to be different given different situations. For example, in humid conditions, the fit of a band may be perceived to be tighter. In another example, a user who is sweating may perceive the fit of a band to be looser. In many cases, these problems can be exacerbated during periods of heightened activity, such as while running or playing sports. 
     Despite the prevalence of issues associated with improperly fit bands, adjusting the size or fit of conventional watch bands often requires multiple steps, specialized tools, and/or technical expertise. For example, a metal link band may require specialized tools to remove one or more links of the band to resize the band. In other cases, a leather band with a deployment clasp may need to be physically cut to size in order to resize the band. 
     In other cases, watch bands may have limited fit adjustment increments available. For example, a conventional watch band may space sizing eyelets approximately 8 mm apart. In some cases, a user may prefer a fit corresponding to a location between two eyelets. In some examples, especially for users having relatively small wrists, an error of ±4 mm (e.g., example of error halfway between “too tight” and “too loose”) can correspond to an error upwards of ±5% of the circumference of that user&#39;s wrist, which, for many users, may be intolerable. 
     As a result, users of conventional wristwatches and/or fitness/health tracking devices may select a tolerable (although not optimally comfortable) fit, reserving tighter bands for fitness/health tracking devices and looser bands for conventional wristwatches. 
     However, as noted above, some wearable electronic devices, such as smart watches, may be multi-purpose devices. For example, many smart watches provide both fitness/health tracking and timekeeping functionality. Thus, many users may wear a smart watch exclusively, instead of periodically switching between wearing a traditional wristwatch and a separate fitness/health tracking device. In these examples, a user may prefer the fit of a smart watch to vary with use. For example, a user may prefer a looser fit in a timekeeping mode and a tighter fit in a fitness/health tracking mode. 
     As may be appreciated, the inconvenience associated with repeated resizing and reattachment of a conventional watchband may contribute to diminishing use of a wearable electronic device, which may, in turn, precipitate a customer retention problem for the manufacturer thereof. In other examples, such as for wearable electronic devices configured to collect health-related information (e.g., pulse rate, blood oxygen saturation, blood pressure, insulin levels, etc.) or to provide health-related notifications (e.g., prescription timing reminders, medical alerts, medical identification numbers, etc.), discontinued use of the wearable electronic device may lead to more serious consequences such as health problems, medical emergencies, and/or incomplete or inconsistent medial data collection. 
     Accordingly, many embodiments described herein relate to systems and methods for dynamic adjustment of the fit of the wearable electronic devices. 
     For example, certain embodiments described herein take the form of methods for adjusting the fit of a wearable electronic device secured by a band to a user. Features of a band can provide a capability to automatically adjust a tightness of a band without active user input. For example, a tensioning element can be provided with a capability to alter the fit of a band in response to heat emitted by a user wearing the band. 
     By further example, the watch can generate a signal with an instruction to adjust the fit of the band, selecting an operational mode (e.g., tightening mode, loosening mode, flexibility mode, rigid mode, etc.) of a tensioner coupled to electronic device, and actuating the tensioning element based on the instruction. 
     The term “tensioning element” and related phrases and terminology is used herein to generally refer to structural component of a band that changes at least one feature thereof to adjust a fit of the band on a wrist or other portion of a user. The term “tensioner” and related phrases and terminology is used herein to generally refer to a circuit, apparatus, controller, or program code executed by a processor, that is configured to cause, either directly or indirectly, tension in a band or strap coupled to an electronic device housing to increase or decrease. For example, a tensioner can apply a stimulus to a tensioning element. 
     In some examples, a tensioning element associated with and/or coupled to the watch can also be coupled to a portion of the band that is configured to compress in response to heat conditions. For example, a shape memory polymer can be formed in a longitudinal (e.g., serpentine) pattern within one or more portions of a band. Body heat of a user and/or heat generated by the watch can be applied to the shape memory polymer to alter its length and thereby increase or decrease the tightness of the band. 
     In other examples, a tensioning element associated with and/or coupled to the watch can also be coupled to a portion of the band that is configured to change an overall shape in response to heat conditions. For example, a shape memory polymer can be formed along one or more portions of a band. Body heat of a user and/or heat generated by the watch can be applied to the shape memory polymer to change its shape and thereby increase or decrease the tightness of the band. 
     In other examples, a tensioning element associated with and/or coupled to the watch can also be coupled to a portion of the band that is configured to change an overall shape in response to heat conditions. For example, a shape memory polymer can be formed within a thickness of at least a portion of the. Body heat of a user and/or heat generated by the watch can be applied to the shape memory polymer to change its thickness and thereby increase or decrease the tightness of the band. 
     These and other embodiments are discussed below with reference to  FIGS.  1 - 18   . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIG.  1    depicts a perspective view of a watch attached by a band to a user. In the illustrated embodiment, the watch  100  is implemented as a portable electronic device that is worn on the wrist of a user  102 . Other embodiments can implement the watch differently. For example, the watch can be a smart phone, a gaming device, a digital music player, a sports accessory device, a medical device, navigation assistant, accessibility device, a device that provides time and/or weather information, a health assistant, and other types of electronic device suitable for attaching to a user. 
     The watch  100  includes a housing  104  and a display  106 . The housing  104  can form an outer surface or partial outer surface and protective case for one or more internal components of the watch  100 . In the illustrated embodiment, the housing  104  is formed into a substantially rectangular shape, although this configuration is not required and other shapes are possible in other embodiments. 
     In some examples, the display  106  may incorporate an input device configured to receive user input. Optionally, a user can provide input to the display  106  to indicate the user&#39;s intention to increase the tightness of the fit of the wearable device. In other examples, the user can provide a force input to the display  106 , the magnitude of which can correspond to the magnitude of tightness increase in the fit the user desires to be implemented by the watch  100 . 
     The display  106  can be implemented with any suitable technology, including, but not limited to, a multi-touch sensing touchscreen that uses liquid crystal display (LCD) technology, light emitting diode (LED) technology, organic light-emitting display (OLED) technology, organic electroluminescence (OEL) technology, or another type of display technology. In many embodiments, the display  106  can be disposed below a protective cover glass formed from a rigid and scratch resistant material such as ion-implanted glass, laminated glass, or sapphire. 
     As noted above, the display  106  can incorporate or be disposed proximate to an input sensor. For example, in some embodiments, the display  106  can also include one or more contact sensors to determine the position of one or more contact locations on a top surface of the display  106 . In some embodiments, the display  106  can also include one or more force-sensitive elements (not shown) to detect a magnitude of force applied to the top surface of the display  106 . 
     The watch  100  can include within the housing  104  a processor, a memory, a power supply and/or battery, network communications, sensors, display screens, acoustic elements, input/output ports, haptic elements, digital and/or analog circuitry for performing and/or coordinating tasks of the watch  100 , and so on. In some examples, the watch  100  can communicate with a separate electronic device via one or more proprietary and/or standardized wired and/or wireless interfaces. For simplicity of illustration, the watch  100  is depicted in  FIG.  1    without many of these elements, each of which may be included, partially, optionally, or entirely, within the housing  104 . 
     The watch  100  can be coupled to the user  102  via a band  108  that loops around the user&#39;s wrist. The band  108  can be formed from a compliant material, or into a compliant structure, that is configured to easily contour to a user&#39;s wrist, while retaining stiffness sufficient to maintain the position and orientation of the watch on the user&#39;s wrist. The material selected for the band  108  may vary from embodiment to embodiment. For example, in certain cases, the band  108  can be formed from metal, such as a band formed into a metal mesh. In other embodiments, the band  108  can be formed from an organic material such as leather. In further examples, the band  108  can be formed from an inorganic material such as nylon. In still further embodiments, materials such as plastic, rubber, or other fibrous, organic, polymeric, or synthetic materials may be used. 
     As can be appreciated, the relative stiffness of a band can impact the tightness with which the band may be fit to a user&#39;s wrist. For example, the more flexible the band  108 , the tighter the band should be secured to prevent the watch  100  from sliding, rotating, or otherwise displacing on the user&#39;s wrist. 
     In some embodiments, the band  108  can be formed, at least in part, from a polymer, such as a fluoroelastomeric polymer, having a Shore durometer selected for having flexibility suitable for easily contouring to a user&#39;s wrists while maintaining sufficient stiffness to maintain support of the watch  100  when attached to the wrist of user  102 . For example, bands of certain embodiments may have a Shore A durometer ranging from 60 to 80 and/or a tensile strength greater than 12 MPa. 
     In some embodiments, a fluoroelastomeric polymer (or other suitable polymer) can be doped or treated with one or more other materials. For example, the polymer can be doped with an agent configured to provide the polymer with a selected color, odor, taste, hardness, elasticity, stiffness, reflectivity, refractive pattern, texture and so on. In other examples, the doping agent can confer other properties to the fluoroelastomeric polymer including, but not necessarily limited to, electrical conductivity and/or insulating properties, magnetic and/or diamagnetic properties, chemical resistance and/or reactivity properties, infrared and/or ultraviolet light absorption and/or reflectivity properties, visible light absorption and/or reflectivity properties, antimicrobial and/or antiviral properties, oleophobic and/or hydrophobic properties, thermal absorption properties, pest repellant properties, colorfast and/or anti-fade properties, deodorant properties, antistatic properties, medicinal properties, liquid exposure reactivity properties, low and/or high friction properties, hypoallergenic properties, and so on. 
     In some embodiments, one or more doping agents may be used. In further embodiments, the doping agents associated with one area of the band  108  may be different from the doping agents associated with another area of the bands. In one example, a band may have a low friction dopant added to the portion of a band that faces a user&#39;s wrist (e.g., bottom surface) while having a high reflectivity dopant added to the portion of the band that faces outwardly (e.g., top surface). 
     Other embodiments described herein include configurations in which the band  108  is formed, at least in part, from a non-compliant material into a compliant structure. For example, a metallic mesh can be used to form band  108 . In other embodiments, the band can be formed by joining a number of metal links. In other embodiments, the band can be formed by joining a number of glass or crystal links. 
     In other embodiments, the band  108  can be formed form a combination of complaint and non-compliant materials. 
     In some examples, the band  108  can be removably coupled to the housing  104 . For example, in certain embodiments, the band  108  can be at least partially looped around a watch pin that is configured to insert within lugs extending from the body of the housing  104 . In other examples, the band  108  can be configured to slide within and be retained by two or more channels within external sidewalls of the housing  104 . In other examples, the band  108  can be looped through and aperture in the housing  104 . In other cases, the band  108  can be riveted, screwed, or otherwise attached to the housing  104  via one or more mechanical fasteners. In still further embodiments, additional removable couplings between the band  108  and the housing  104  are possible. 
     In other examples, the band  108  can be permanently coupled to the housing  104 . For example, in some cases, the band  108  may be formed as an integral portion of the housing  104 . In other cases, the band  108  can be rigidly adhered to the housing  104  via an adhesive. In still further embodiments, the band  108  can be welded, soldered, or chemically bonded to the housing  104 . In other embodiments, additional permanent couplings between the band  108  and the housing  104  are possible. 
     As noted above, the housing  104  may be rigid and can be configured to provide structural support and impact resistance for electronic or mechanical components contained therein. A rigid housing is not necessarily required for all embodiments and, in some examples, the watch  100  can have a housing may be flexible. Furthermore, although watch housings are typically formed to take a rectangular shape, this is not required and other shapes are possible. For example, certain housings may take a circular shape. 
     In other embodiments, the watch  100  can include one or more sensors (not shown) positioned on a bottom surface of the housing  104 . Sensors utilized by the watch  100  can vary from embodiment to embodiment. Suitable sensors can include temperature sensors, electrodermal sensors, blood pressure sensors, heart rate sensors, respiration rate sensors, oxygen saturation sensors, plethysmographic sensors, activity sensors, pedometers, blood glucose sensors, body weight sensors, body fat sensors, blood alcohol sensors, dietary sensors, and so on. 
     In many cases, sensors such as biometric sensors can collect certain health-related information non-invasively. For example, the watch  100  can include a sensor that is configured to measure changes in (or an amount of) light reflected from a measurement site (e.g., wrist) of the user  102 . In one embodiment, the biometric sensor such as a PPG sensor can include a light source for emitting light onto or into the wrist of the user  102  and an optical sensor to detect light exiting the wrist of the user  102 . Light from the light source may be scattered, absorbed, and/or reflected throughout the measurement sight as a function of various physiological parameters or characteristics of the user  102 . For example, the tissue of the wrist of the user  102  can scatter, absorb, or reflect light emitted by the light source differently depending on various physiological characteristics of the surface and subsurface of the user&#39;s wrist. 
     In many cases a PPG sensor can be used to detect a user&#39;s heart rate and blood oxygenation. For example, during each complete heartbeat, a user&#39;s subcutaneous tissue can distend and contract, alternatingly increasing and decreasing the light absorption capacity of the measurement site. In these embodiments, the optical sensor of the PPG can collect light exiting the measurement site and generate electrical signals corresponding to the collected light. Thereafter, the electrical signals can be conveyed as raw data to the watch  100 , which in turn can process the raw data into health data  110 . The raw data can be based on information about the collected light, such as the chromaticity and/or luminance of the light. In some cases, the health data  110  can be shown on the display  106  as biometric feedback to the user  102 . 
     However, certain sensors such as PPG sensors may be susceptible to noise associated with ambient light, surface conditions of the measurement site (e.g., cleanliness, hair, perspiration, etc.), proximity of the optical sensor and/or light source to the measurement site, and motion artifacts caused by the relative motion between the watch  100  and the user  102 . As a result, if the watch  100  is not snugly fit to the user  102  (at least while the PPG sensor is obtaining a measurement), the health data  110  obtained from the sensor may be sub-optimal (e.g., insufficient or insignificant magnitude) as a direct result of the improper fit. Alternatively, if the watch  100  is snugly fit to the user  102 , the health data  110  obtained from the sensor may be of substantially improved quality, magnitude, and clarity. 
     It will be understood that in certain embodiments, the watch  100  may dynamically resize the band  108  and/or the fit of the watch  100  for reasons unrelated to sensor data quality. For example, as mentioned above, a tensioning element (not shown) can be coupled to the watch  100 . In some examples, the tensioning element can be included within the housing  104 . In other examples, the tensioning element can be included within the band  108 . In still further examples, a portion of the tensioning element can be included within the housing  104  and a portion of the tensioning element can be included within the band  108 . In some examples, the tensioning element can be coupled to the band  108  and to the housing  104 . For example, the tensioning element can take the form of a coupling and/or a lug by which the band  108  couples to the housing  104 . 
       FIGS.  2 - 4    depict side views of a watch  200  with a band  208  for attaching to a user. The watch  200  can include one or more of the features discussed herein with respect to the watch  100 . For example, as with the embodiment depicted in  FIG.  1   , the watch  200  can include a housing  204  and a display that may incorporate an input device configured to receive touch input, force input, or other input from a user. The housing  204  may also include one or more buttons or input ports (not shown). The housing  204  can be permanently or removably attached to a band  208 . 
     As with the embodiment depicted in  FIG.  1   , the band  208  can be formed from a compliant material or into a compliant structure that is configured to easily contour to a user&#39;s wrist, while retaining stiffness sufficient to maintain the position and orientation of the watch on the user&#39;s wrist. The band  208  is illustrated as a single, continuous structure extending from opposing ends of the housing  204 . Additionally or alternatively, the band  208  can include overlapped components to form a closed loop around a user&#39;s wrist. In these examples, the separate components can be affixed together with a traditional or conventional attachment mechanism. For example, in some embodiments, a buckling clasp can be used. In other examples a pin and eyelet attachment mechanism can be used. 
     The watch  200  can include a tensioner (not illustrated) in order to provide dynamic adjustment of the fit of the watch  200 . As with other embodiments described herein, the tensioner may alter the fit of the watch  200  in a number of ways. For example, the tensioner can adjust one or more dimensions of a band coupled to the watch. In another example, the tensioner can adjust a coupling between a band and the watch. In another example the tensioner can adjust the position of the housing of the watch relative to the band. In still other embodiments, other adjustments are possible. 
     In some embodiments, as shown in  FIG.  2   , the length of the band  208  can be increased or decreased in order to adjust the fit of the watch  200 . This type of adjustment can be referred to as a “fastening force.” In these embodiments, the shorter the length of the band  208 , the tighter the fit of the watch  200  may be. Similarly, the longer the length of the band  208 , the looser the fit of the watch  200  may be. Length adjustments to the band  208  are shown in  FIG.  2    with bi-directional arrows. As shown, the length need not change along every portion of the band  208 . 
     In some embodiments, as shown in  FIG.  3   , the shape of the band  208  can be adjusted in order to adjust the fit of the watch  200 . This type of adjustment can be referred to as a “coiling force.” For example, a cross-sectional shape of the band  208  can be defined by an inner periphery of the band  208 , such as along a user engagement surface of the band  208 . The band  208  can define multiple cross-sectional dimensions, defined by a distance between opposing inner surfaces of the band  208 . It will be understood that the housing  204  can also provide an end that defines the cross-sectional dimension. Where a change of the shape of the band  208  changes at least one cross-sectional dimension of the band  208 , the fit of the watch  200  can be altered by changing a force applied by the portions of the band  208  that define the altered cross-sectional dimension. In these embodiments, the shorter the cross-sectional dimension of the band  208 , the tighter the fit of the watch  200  may be. Similarly, the greater the cross-sectional dimension of the band  208 , the looser the fit of the watch  200  may be. Shape adjustments to the band  208  are shown in  FIG.  3    with bi-directional arrows. As shown, the shape need not change along every portion of the band  208 . 
     In some embodiments, as shown in  FIG.  4   , the thickness of the band  208  can be increased or decreased in order to adjust the fit of the watch  200 . This type of adjustment can be referred to as a “pressure.” In these embodiments, the thicker the band  208 , the tighter the fit of the watch  200  may be. Similarly, the thinner the band  208 , the looser the fit of the watch  200  may be. Thickness adjustments to the band  208  are shown in  FIG.  4    with a bi-directional arrows. As shown, the thickness need not change along every portion of the band  208 . 
     It will be understood that any given band can provide one or more of the adjustments illustrated in  FIGS.  2 - 4    and/or other adjustments. It will be further understood that the adjustments illustrated in  FIGS.  2 - 4    and/or other adjustments may apply equally or equivalently to other band and/or watch embodiments described herein. More generally, it should be appreciated that the various examples and embodiments presented herein can apply equally or equivalently to many band and/or watches and no single embodiment, or adjustments thereto by a tensioner or the watch itself, should be considered as limited to that single embodiment. 
       FIG.  5    depicts a simplified block diagram of a watch  300  configured to be coupled to a user with a band about the user&#39;s wrist. The watch  300  can one or more processing devices  306 , memory  308 , one or more input/output (I/O) devices or sensors  310  (e.g., biometric sensors, environmental sensors, etc.), one or more displays  312 , one or more power source(s) (not shown), one or more physical and/or rotary input devices  314 , one or more touch and/or force input device(s)  316 , one or more acoustic input and/or output devices  318 , one or more haptic output device(s)  320 , one or more a network communication interface(s)  322 , and one or more tensioner  324 . Some embodiments can also include additional components. 
     The display  312  may provide an image or video output for the watch  300 . The display  312  may also provide an input surface for one or more input devices such as a touch sensing device  316 , force sensing device, temperature sensing device, and/or a fingerprint sensor. The display  312  may be any size suitable for inclusion at least partially within the housing of the watch  300  and may be positioned substantially anywhere on the watch  300 . In some embodiments, the display  312  can be protected by a cover glass formed from a scratch-resistant material (e.g., sapphire, zirconia, glass, and so on) that may form a substantially continuous external surface with the housing of the watch  300 . 
     The processing device(s)  306  can control or coordinate some or all of the operations of the watch  300 . The processing device  306  can communicate, either directly or indirectly with substantially all of the components of the watch  300 . For example, a system bus or signal line or other communication mechanisms can provide communication between the processing device  306 , the memory  308 , the I/O device(s)  310 , the power source(s), the network communication interface  322 , and/or the haptic output device  320 . 
     The one or more processing devices  306  can be implemented as any electronic device capable of processing, receiving, or transmitting data or instructions. For example, the processing device(s)  306  can each be a microprocessor, a central processing unit (CPU), an application-specific integrated circuit (ASIC), a digital signal processor (DSP), or combinations of such devices. As described herein, the term “processing device” is meant to encompass a single processor or processing unit, multiple processors, multiple processing units, or other suitably configured computing element or elements. 
     The memory  308  can store electronic data that can be used by the watch  300 . For example, a memory can store electrical data or content such as, for example, audio and video files, documents and applications, device settings and user preferences, timing and control signals or data for the haptic output device  320 , data structures or databases, and so on. The memory  308  can be configured as any type of memory. By way of example only, the memory can be implemented as random access memory, read-only memory, Flash memory, removable memory, or other types of storage elements, or combinations of such devices. 
     The one or more I/O device(s)  310  can transmit and/or receive data to and from a user or another electronic device. The I/O device(s)  310  can include a touch sensing input surface such as one or more buttons, one or more microphones or speakers, and/or one or more ports such as a microphone port. 
     The watch  300  may also include one or more sensors  310  positioned substantially anywhere on the watch  300 . The sensor or sensors  310  may be configured to sense substantially any type of characteristic such as, but not limited to, images, pressure, light, touch, force, temperature, position, motion, and so on. For example, the sensor(s)  310  may be an image sensor, a temperature sensor, a light or optical sensor, an atmospheric pressure sensor, a humidity sensor, a magnet, a gyroscope, an accelerometer, and so on. In other examples, the watch  300  may include one or more health sensors. In some examples, the health sensors can be disposed on a bottom surface of the housing of the watch  300 . 
     The power source can be implemented with any device capable of providing energy to the watch  300 . For example, the power source can be one or more batteries or rechargeable batteries, or a connection cable that connects the remote control device to another power source such as a wall outlet. In other examples, wireless power can be used. 
     The network communication interface  322  can facilitate transmission of data to or from other electronic devices across standardized or proprietary protocols. For example, a network communication interface can transmit electronic signals via a wireless and/or wired network connection. Examples of wireless and wired network connections include, but are not limited to, cellular, Wi-Fi, Bluetooth, infrared, and Ethernet. 
     The haptic output device  320  can be implemented as any suitable device configured to provide force feedback, vibratory feedback, tactile sensations, and the like. For example, in one embodiment, the haptic output device  320  may be implemented as a linear actuator configured to provide a punctuated haptic feedback, such as a tap or a knock. 
     As noted above, the watch  300  can include a tensioner  324 . In some embodiments, a tensioner can be an analog, digital, or integrated circuit configured to apply a stimulus to cause tension (either directly or indirectly) to be applied to, or relieved form, the band. For example, a tensioner can apply heat and/or another stimulus directly and/or indirectly to the band to induce a temperature and/or a temperature change and cause the band to adjust a feature thereof and thereby adjust a fit on a user. 
     As noted above, the signal to change the fit of the watch  300  can be received from any number of sources. For example, in certain embodiments, the signal can be received from secondary electronic device through the network communication interface  322 . In other embodiments, the signal can be received as direct user input. For example, a user can provide input to the touch sensing device  316  of the watch  300  to indicate to the watch  300  and/or the tensioner  324  the user&#39;s desire for the fit of the device to change, either with increased tightness or decreased tightness. 
     Referring now to  FIG.  6   , a watch band can provide an ability to adjust a fit on a user with interwoven strands. For example, a watch band can include at least one strand of a shape memory polymer that changes a characteristic thereof in response to a stimulus, such as heat and/or an induced temperature or temperature change. The shape memory polymer can provide an ability to reversibly change the fit of the watch band. 
       FIG.  6    illustrates a view of a watch  400  with a band  408  for securing a housing  404  to a user. The watch  400  can include one or more of the features discussed herein with respect to the watch  100 , the watch  200 , and/or the watch  300 . For example, as with the embodiment depicted in  FIG.  1   , the watch  400  can include a housing  404  with a display that may incorporate an input device configured to receive touch input, force input, or other input from a user. The housing  404  may also include one or more buttons or input ports (not shown). The housing  404  can be permanently or removably attached to the band  408 . 
     As further shown in  FIG.  6   , the band  408  can be formed as a fabric  410  of interwoven strands. For example, a number of strands can include one or more warp strands and one or more weft strands combined in a plain weave or another type of weave. In general, the fabric  410  may include any intertwined strands (woven, knitted, braided, etc.). The plain weave fabric of  FIG.  6    is merely illustrative, and it will be appreciated that other weave configurations are contemplated. 
     Some or all of the strands can include tensioning elements that respond to a stimulus and adjust a fit of the band. For example, as shown in  FIG.  6   , at least some of the warp strands can include tensioning elements  450  among other warp strands  430 . In some embodiments, the tensioning elements  450  can be positioned along an inner section of the fabric  410 , and the other warp strands  430  can be positioned along outer sections of the fabric  410 , such as those defining, at least in part, an outer edge of the fabric  410 . Additionally or alternatively, the tensioning elements  450  can be positioned along outer sections of the fabric  410  and/or all of the warp strands can be tensioning elements  450 . Additionally or alternatively, one or more weft strands  420  can be tensioning elements. 
     The tensioning elements  450  can include one or more shape memory polymers that respond to a stimulus, such as heat. For example, the user and/or the watch can apply a stimulus, such as heat and/or an induced temperature or temperature change to the tensioning elements  450 . Such a stimulus can be applied passively, such as when the band  408  is worn by a user, when the user raises the user&#39;s own body temperature, and/or when a user increases an amount of heat emitted. Additionally or alternatively, a stimulus can be actively applied, such as by a tensioner operated at the housing  404  of the watch  400  to emit heat and/or induce a temperature or temperature change in the tensioning elements  450 . In response, the shape memory polymer of the tensioning elements  450  can provide an ability to reversibly change the fit of the watch band by changing a characteristic of the tensioning elements  450 . For example, the tensioning elements  450  can change to adjust a length of the band  408  in a manner similar to the change illustrated in  FIG.  2   . By further example, the tensioning elements  450  can change to adjust a shape of the band  408  in a manner similar to the change illustrated in  FIG.  3   . By further example, the tensioning elements  450  can change to adjust a thickness of the band  408  in a manner similar to the change illustrated in  FIG.  4   . Other components of the band  408  (e.g., other warp strands and/or weft strands) can adjust to match or otherwise accommodate the change in the tensioning elements  450 . Accordingly, the tensioning elements  450  can respond to a stimulus to adjust a fit of the band  408  on a wrist of the user. 
     Referring now to  FIGS.  7  and  8   , a watch band can provide an ability to adjust a fit on a user with a tensioning element that changes between a straight configuration and a curved configuration. For example, a watch band can include at least one tensioning element of a shape memory polymer that changes a characteristic thereof in response to a stimulus, such as heat and/or an induced temperature or temperature change. The shape memory polymer can provide an ability to reversibly change the fit of the watch band. 
       FIGS.  7  and  8    illustrate views of a watch  500  with a band  508  for securing a housing  504  to a user. The watch  500  can include one or more of the features discussed herein with respect to the watch  100 , the watch  200 , and/or the watch  300 . For example, as with the embodiment depicted in  FIG.  1   , the watch  500  can include a housing  504  with a display that may incorporate an input device configured to receive touch input, force input, or other input from a user. The housing  504  may also include one or more buttons or input ports (not shown). The housing  504  can be permanently or removably attached to the band  508 . 
     As shown in  FIG.  7   , the band  508  can include one or more tensioning elements  550  optionally within or otherwise coupled to a cover  520 . The cover  520  can be formed from a material having flexibility suitable for easily contouring to a user&#39;s wrists while maintaining sufficient stiffness to maintain support of the watch  500  when attached to the wrist of user. The tensioning elements  550  can extend within and/or along the cover  520  and coupled thereto at least at the ends of the tensioning elements  550 . The tensioning elements  550  can optionally extend along an entirety or only a portion of a total length of the band  508 . In some embodiments, the tensioning elements  550  are positioned opposite the housing  504 . 
     Some or all of the tensioning elements can respond to a stimulus and adjust a fit of the band. For example, as shown in  FIG.  7   , the tensioning elements  550  can have a straight configuration. In the straight configuration, the tensioning elements  550  can be substantially straight. As used herein, a tensioning element is substantially straight when the curvature thereof does not cause a total width of the shape formed by the tensioning element to be more than double the cross-sectional dimension at any portion of the tensioning element. Where multiple tensioning elements  550  are provided, the tensioning elements  550  can be substantially parallel to each other while in the straight configuration. 
     By further example, as shown in  FIG.  8   , the tensioning elements  550  can have a curved configuration. In the curved configuration, the tensioning elements  550  can be substantially curved and/or serpentine. As used herein, a tensioning element is substantially curved and/or serpentine when the curvature thereof causes a total width of the shape formed by the tensioning element to be more than double the cross-sectional dimension at any portion of the tensioning element. As such, the induced curvature along the length of the tensioning elements  550  can shorten the total length thereof, thereby creating tension and shortening of the length of the band  508 . 
     The tensioning elements  550  can include one or more shape memory polymers that respond to a stimulus, such as heat. For example, the user and/or the watch can apply a stimulus, such as heat and/or an induced temperature or temperature change to the tensioning elements  550 . Such a stimulus can be applied passively, such as when the band  508  is worn by a user, when the user raises the user&#39;s own body temperature, and/or when a user increases an amount of heat emitted. Additionally or alternatively, a stimulus can be actively applied, such as by a tensioner operated at the housing  504  of the watch  500  to emit heat and/or induce a temperature or temperature change in the tensioning elements  550 . In response, the shape memory polymer of the tensioning elements  550  can provide an ability to reversibly change the fit of the watch band by changing a characteristic of the tensioning elements  550 . For example, the tensioning elements  550  can change to adjust a length of the band  508  in a manner similar to the change illustrated in  FIG.  2   . By further example, the tensioning elements  550  can change to adjust a shape of the band  508  in a manner similar to the change illustrated in  FIG.  3   . By further example, the tensioning elements  550  can change to adjust a thickness of the band  508  in a manner similar to the change illustrated in  FIG.  4   . Other components of the band  508  (e.g., the cover  520 ) can adjust to match or otherwise accommodate the change in the tensioning elements  550 . Accordingly, the tensioning elements  550  can respond to a stimulus to adjust a fit of the band  508  on a wrist of the user. 
     Referring now to  FIGS.  9  and  10   , a watch band can provide an ability to adjust a fit on a user with a tensioning element that changes between an extended configuration and a retracted configuration. For example, a watch band can include at least one tensioning element of a shape memory polymer that changes a characteristic thereof in response to a stimulus, such as heat and/or an induced temperature or temperature change. The shape memory polymer can provide an ability to reversibly change the fit of the watch band. 
       FIGS.  9  and  10    illustrate views of a watch  600  with a band  608  for securing a housing  604  to a user. The watch  600  can include one or more of the features discussed herein with respect to the watch  100 , the watch  200 , and/or the watch  300 . For example, as with the embodiment depicted in  FIG.  1   , the watch  600  can include a housing  604  with a display that may incorporate an input device configured to receive touch input, force input, or other input from a user. The housing  604  may also include one or more buttons or input ports (not shown). The housing  604  can be permanently or removably attached to the band  608 . 
     As shown in  FIG.  9   , the band  608  can include one or more tensioning elements  650  optionally within or otherwise coupled to a cover  620 . The cover  620  can be formed from a material having flexibility suitable for easily contouring to a user&#39;s wrists while maintaining sufficient stiffness to maintain support of the watch  600  when attached to the wrist of user. The tensioning elements  650  can extend within and/or along the cover  620  and coupled thereto at least at the ends of the tensioning elements  650 . The tensioning elements  650  can optionally extend along an entirety or only a portion of a total length of the band  608 . In some embodiments, the tensioning elements  650  extend away from the housing  604  while the band  608  is coupled thereto. The tensioning elements  650  may extend away from opposing sides of the housing  604 , such that opposing tensioning elements  650  do or do not reach each other in a region of the band  608  that is opposite the housing  604 . Multiple tensioning elements  650  can extend (e.g., in parallel) from either or both of the ends of the housing  604  (e.g., at watch engagement elements at the ends of the band  608 ). 
     Some or all of the tensioning elements can respond to a stimulus and adjust a fit of the band. For example, as shown in  FIG.  10   , the tensioning elements  650  can have an extended configuration. In the extended configuration, the tensioning elements  650  can define an end that is a distance away from the housing  604 . By further example, as further shown in  FIG.  10   , the tensioning elements  650  can have a retracted configuration. In the retracted configuration, the tensioning elements  650  can shift to bring ends or another portion thereof closer to the housing  604 . As such, the induced change along the length of the tensioning elements  650  can change a distance between the band  608  and the housing  604 , thereby creating a tighter fit on the wrist of the user. 
     The tensioning elements  650  can include one or more shape memory polymers that respond to a stimulus, such as heat. For example, the user and/or the watch can apply a stimulus, such as heat and/or an induced temperature or temperature change to the tensioning elements  650 . Such a stimulus can be applied passively, such as when the band  608  is worn by a user, when the user raises the user&#39;s own body temperature, and/or when a user increases an amount of heat emitted. Additionally or alternatively, a stimulus can be actively applied, such as by a tensioner operated at the housing  604  of the watch  600  to emit heat and/or induce a temperature or temperature change in the tensioning elements  650 . In response, the shape memory polymer of the tensioning elements  650  can provide an ability to reversibly change the fit of the watch band by changing a characteristic of the tensioning elements  650 . For example, the tensioning elements  650  can change to adjust a length of the band  608  in a manner similar to the change illustrated in  FIG.  2   . By further example, the tensioning elements  650  can change to adjust a shape of the band  608  in a manner similar to the change illustrated in  FIG.  3   . By further example, the tensioning elements  650  can change to adjust a thickness of the band  608  in a manner similar to the change illustrated in  FIG.  4   . Other components of the band  608  (e.g., the cover  620 ) can adjust to match or otherwise accommodate the change in the tensioning elements  650 . Accordingly, the tensioning elements  650  can respond to a stimulus to adjust a fit of the band  608  on a wrist of the user. 
     Referring now to  FIGS.  11 - 13   , a watch band can provide an ability to adjust a fit on a user with a tensioning element that changes between a straight configuration and a curved configuration. For example, a watch band can include at least one tensioning element of a shape memory polymer that changes a characteristic thereof in response to a stimulus, such as heat and/or an induced temperature or temperature change. The shape memory polymer can provide an ability to reversibly change the fit of the watch band. 
       FIGS.  11  and  12    illustrate views of a watch  700  with a band  708  for securing a housing  704  to a user. The watch  700  can include one or more of the features discussed herein with respect to the watch  100 , the watch  200 , and/or the watch  300 . For example, as with the embodiment depicted in  FIG.  1   , the watch  700  can include a housing  704  with a display that may incorporate an input device configured to receive touch input, force input, or other input from a user. The housing  704  may also include one or more buttons or input ports (not shown). The housing  704  can be permanently or removably attached to the band  708 . 
     As shown in  FIG.  11   , the band  708  can include one or more tensioning elements  750  optionally within or otherwise coupled to a cover  720 . The cover  720  can be formed from a material having flexibility suitable for easily contouring to a user&#39;s wrists while maintaining sufficient stiffness to maintain support of the watch  700  when attached to the wrist of user. The tensioning elements  750  can extend within and/or along the cover  720  and coupled thereto at least at the ends of the tensioning elements  750 . The tensioning elements  750  can optionally extend along an entirety or only a portion of a total length of the band  708 . In some embodiments, the tensioning elements  750  extend away from the housing  704  while the band  708  is coupled thereto. The tensioning elements  750  may extend away from opposing sides of the housing  704 , such that opposing tensioning elements  750  do or do not reach each other in a region of the band  708  that is opposite the housing  704 . 
     Some or all of the tensioning elements can respond to a stimulus and adjust a fit of the band. For example, the tensioning elements  750  can have an extended configuration. In the extended configuration, the tensioning elements  750  can define an end that is a distance away from the housing  704 . By further example, the tensioning elements  750  can have a retracted configuration. In the retracted configuration, the tensioning elements  750  can shift to bring ends or another portion thereof closer to the housing  704  and/or toward each other. As such, the induced change along the length of the tensioning elements  750  can change a distance between the band  708  and the housing  704 , thereby creating a tighter fit on the wrist of the user. 
     The tensioning elements  750  can include one or more stacked layers that provide, individually or in combination, different responses along a length of the band  708 . For example, as shown in  FIGS.  12  and  13   , a given one of the tensioning elements  750  can include a first layer  752 , a second layer  754 , a third layer  756 , and/or a fourth layer  758 . It will be understood that fewer and/or a greater number of layers can be included. Each of the layers can extend a different distance and/or to a different portion of the band  708 . For example, each of the layers can extend from a single location, such as from a watch engagement element of the band  708  where the band  708  attaches to the housing  704 . Each of the layers can further extend to a different location. The length of each layer can be longer and/or shorter than that of an adjacent layer. For example, the shortest one of the layers can be closer than any other layer to an inner or outer surface of the band  708 . By further example, the longest one of the layers can be closer than any other layer to an inner or outer surface of the band  708 . The layers can be of the same or different materials. The layers can have the same or different widths. The layers can have the same or different thicknesses. The arrangement of the layers and characteristics thereof can allow the tensioning elements  750  to provide different responses to a single stimulus along the length of the band  708 . 
     The tensioning elements  750  can include one or more shape memory polymers that respond to a stimulus, such as heat. For example, the user and/or the watch can apply a stimulus, such as heat and/or an induced temperature or temperature change to the tensioning elements  750 . Such a stimulus can be applied passively, such as when the band  708  is worn by a user, when the user raises the user&#39;s own body temperature, and/or when a user increases an amount of heat emitted. Additionally or alternatively, a stimulus can be actively applied, such as by a tensioner operated at the housing  704  of the watch  700  to emit heat and/or induce a temperature or temperature change in the tensioning elements  750 . In response, the shape memory polymer of the tensioning elements  750  can provide an ability to reversibly change the fit of the watch band by changing a characteristic of the tensioning elements  750 . For example, the tensioning elements  750  can change to adjust a length of the band  708  in a manner similar to the change illustrated in  FIG.  2   . By further example, the tensioning elements  750  can change to adjust a shape of the band  708  in a manner similar to the change illustrated in  FIG.  3   . By further example, the tensioning elements  750  can change to adjust a thickness of the band  708  in a manner similar to the change illustrated in  FIG.  4   . Other components of the band  708  (e.g., the cover  720 ) can adjust to match or otherwise accommodate the change in the tensioning elements  750 . Accordingly, the tensioning elements  750  can respond to a stimulus to adjust a fit of the band  708  on a wrist of the user. 
     Referring now to  FIG.  14   , a watch band can provide an ability to adjust a fit on a user with a tensioning element that is one of multiple layers forming the watch band. For example, a watch band can include at least one tensioning element layer of a shape memory polymer that changes a characteristic thereof in response to a stimulus, such as heat and/or an induced temperature or temperature change. The shape memory polymer can provide an ability to reversibly change the fit of the watch band. 
       FIG.  14    illustrates a view of a band  808  for securing a housing to a user. The watch can include one or more of the features discussed herein with respect to the watch  100 , the watch  200 , and/or the watch  300 . For example, as with the embodiment depicted in  FIG.  1   , the watch can include a housing with a display that may incorporate an input device configured to receive touch input, force input, or other input from a user. The housing may also include one or more buttons or input ports (not shown). The housing can be permanently or removably attached to the band. 
     As shown in  FIG.  14   , the band  808  can include multiple layers. The tensioning element  850  can form a layer, such as an exterior layer of the band  808 . At least one other layer, such as a support layer  820 , can be provided. The support layer  820  can be formed from a material having flexibility suitable for easily contouring to a user&#39;s wrists while maintaining sufficient stiffness to maintain support of the watch  800  when attached to the wrist of user. The tensioning element  850  can be coupled to the support layer  820  by a buffer layer  830  that facilitates secure coupling and flexion between the support layer  820  and the tensioning element  850 . 
     Some or all of the tensioning elements can respond to a stimulus and adjust a fit of the band. For example, the tensioning element  850  can have a deployed configuration. In the deployed configuration, portions of the tensioning element  850  can extend away from each other. By further example, as shown in  FIG.  15   , the tensioning element  850  can have a folded configuration. In the folded configuration, the tensioning element  850  forms folds  810  and moves portions of thereof toward each other to change a feature of the band  808 . As such, the induced change along the length of the tensioning element  850  can create a tighter fit on the wrist of the user. While one example of a folded configuration is illustrated, it will be understood that a variety folds can be made. The band  808  can form undulating patterns, corrugation, bellows, origami shapes, and the like. Folding patterns can be selected based on desired softness and gripping capabilities of the band. 
     The tensioning element  850  can include one or more shape memory polymers that respond to a stimulus, such as heat. For example, the user and/or the watch can apply a stimulus, such as heat and/or an induced temperature or temperature change to the tensioning element  850 . Such a stimulus can be applied passively, such as when the band  808  is worn by a user, when the user raises the user&#39;s own body temperature, and/or when a user increases an amount of heat emitted. Additionally or alternatively, a stimulus can be actively applied, such as by a tensioner operated at the housing  804  of the watch  800  to emit heat and/or induce a temperature or temperature change in the tensioning element  850 . In response, the shape memory polymer of the tensioning element  850  can provide an ability to reversibly change the fit of the watch band by changing a characteristic of the tensioning element  850 . For example, the tensioning element  850  can change to adjust a length of the band  808  in a manner similar to the change illustrated in  FIG.  2   . By further example, the tensioning element  850  can change to adjust a shape of the band  808  in a manner similar to the change illustrated in  FIG.  3   . By further example, the tensioning element  850  can change to adjust a thickness of the band  808  in a manner similar to the change illustrated in  FIG.  4   . Other components of the band  808  (e.g., the buffer layer  830  and/or the support layer  820 ) can adjust to match or otherwise accommodate the change in the tensioning element  850 . Accordingly, the tensioning element  850  can respond to a stimulus to adjust a fit of the band  808  on a wrist of the user. 
     In the embodiments disclosed herein, a shape memory polymer can be provided to respond to a stimulus. In some embodiments, the shape memory polymer is a Tm-type shape memory polymer with a crystalline switching segment. In some embodiments, the shape memory polymer is a Tg-type shape memory polymer with an amorphous switching temperature. 
     A Tm-type shape memory polymer is characterized by high durability under cyclic stretching, high speed response of shape recovering, and drastic moduli drop by shape recovering. In some embodiments, the drop in moduli can be mitigated by forming a composite polymer. In some embodiments, the molecular structure can be controlled to realize controllable stress induced crystallization, which is introduced at limited strain range under stretching. Accordingly, a band of a Tm-type shape memory polymer can be provided with characteristics to cover the wide range of wrist sizes and shapes. In addition to a fastening force (as shown in  FIG.  2   ), such a band can apply both coiling force (as shown in  FIG.  3   ) and pressure (as shown in  FIG.  4   ) to realize a suitable fit by using both Tg- and Tm-type shape memory polymers. 
     A Tm-type shape memory polymer (e.g., Poly ε-caprolactone) has shown stress-induced crystallization under stretching.  FIG.  16    shows PCL-SMP tensile load-displacement curve up to about 5 times elongation. The first loading of the load-displacement curve shows discontinuous jump-up points under the plastic strain region, which is recognized as conventional stress-induced crystallization. After deloading, reloading is achieved without shape recovering, which shows a large tangential value to compare with the first loading. Notably, there is no discontinuous jump-up point, which indicates stress-induced crystallization in PCL-SMP, which breaks with a higher load than the first loading. By controlling the molecular structure to unify the strain value for initiation of stress-induced crystallization, an ideal load-displacement curve can be achieved for a desired fit of a band. 
       FIG.  17    shows a graph with an ideal load-displacement curve for a band. The shape of the load-displacement curve is similar to the line in  FIG.  16   . The required elongation to allow a user to don a band (e.g., over the hand) is about 100% (e.g., double the band length). An adjustable range of band length for individual persons is about 50 mm with almost constant fastening load about from 1N to 2N, this might be possible to design the PCL-SMP. 
     In order to eliminate the moduli drop by shape recovering of Tm-type shape memory polymers, a composite shape memory polymer can be provided. For example, a composite shape memory polymer can include a blend of a Tm-type shape memory polymer and a Tg-type shape memory polymer. 
       FIG.  18    shows data from an example of a shape memory polymer composite that avoids significant moduli drop by shape recovering. One or more of a variety of shape reinforcing materials can be included in a composite shape memory polymer. As shown in  FIG.  18   , a monolithic shape memory polymer is compared to a composite shape memory polymer. A significant difference is demonstrated in the moduli drop between a monolithic Tm-type SMP and a composite Tm-type shape memory polymer. With the combination of 50% volume fraction of 20 MPa moduli particles, the moduli drop is about 10/14. Thus, the moduli decreases down to 71% (i.e., 29% lost). In contrast, that of the monolithic Tm-type shape memory polymer is about 1/16, so the moduli decrease down to 6% (i.e., 94% lost) immediately. Accordingly, by using a composite shape memory polymer, significant moduli drop can be avoided. 
     Accordingly, watch bands described herein can be provided with an ability to dynamically adjust the fit of a watch against a wrist of a user. One or more of a variety of tensioning elements can be provided with a shape memory polymer that responds to a stimulus to adjust a fit of the band. Such stimulus can be from user or actively applied by the watch. The shape memory polymer can be a composite material that provides high durability under cyclic stretching and high speed response of shape recovering while avoiding a drastic moduli drop by shape recovering 
     Various examples of aspects of the disclosure are described below as clauses for convenience. These are provided as examples, and do not limit the subject technology. 
     Clause A: a watch band comprising: warp strands formed by tensioning elements comprising shape memory polymer; and weft strands interwoven with the warp strands, wherein the warp strands are configured to adjust a fit of the watch band in response to an induced temperature. 
     Clause B: a watch band comprising: a cover defining ends configured to engage a housing of a watch; a tensioning element between the ends of the cover, the tensioning element comprising a shape memory polymer and being configured to transition, based on an induced temperature, between: a first configuration in which the tensioning element is substantially straight; and a second configuration in which the tensioning element is substantially serpentine. 
     Clause C: A watch band comprising: a watch engagement element configured to engage a housing of a watch; tensioning elements each comprising multiple tensioning layers extending away from the watch engagement element, each one of the tensioning layers extending a different distance from the watch engagement element, the tensioning layers comprising one or more shape memory polymers. 
     One or more of the above clauses can include one or more of the features described below. It is noted that any of the following clauses may be combined in any combination with each other, and placed into a respective independent clause, e.g., clause A, B, or C. 
     Clause 1: the warp strands are inner warp strands; and the watch band further comprises: a first outer warp strand; and a second outer warp strand opposite the first outer warp strand, wherein the inner warp strands are between the first outer warp strand and the second outer warp strand. 
     Clause 2: the tensioning elements are configured to adjust a fit of the watch band in response to heat emitted from a wrist of a user when the watch band is worn on the wrist. 
     Clause 3: the tensioning elements are configured to respond to a stimulus to adjust a fastening force of the watch band on a wrist of a user. 
     Clause 4: the tensioning elements are configured to respond to a stimulus to adjust a coiling force of the watch band on a wrist of a user. 
     Clause 5: the tensioning elements are configured to respond to a stimulus to adjust a pressure of the watch band on a wrist of a user. 
     Clause 6: the tensioning element is a first tensioning element; and the watch band further comprises a second tensioning element that, while in the first configuration, is parallel to the first tensioning element. 
     Clause 7: the tensioning element is configured to adjust a fit of the watch band in response to heat emitted from a wrist of a user when the watch band is worn on the wrist. 
     Clause 8: the watch band defined an inner surface and an outer surface, wherein a shortest one of the tensioning layers is closer to the outer surface than any other one of the tensioning layers, and a longest one of the tensioning layers is closer to the inner surface than is any other one of the tensioning layers. 
     Clause 9: each of the tensioning elements are configured to transition between: a first configuration in which the tensioning elements are a first distance away from each other; and a second configuration in which the tensioning elements are a second distance away from each other. 
     Clause 10: at least two of the tensioning layers have different thicknesses. 
     Clause 11: at least two of the tensioning layers have different widths. 
     Clause 12: the tensioning elements are configured to adjust a fit of the watch band in response to heat emitted from a wrist of a user when the watch band is worn on the wrist. 
     Clause 13: the tensioning elements are configured to respond to a stimulus to adjust at least one of a fastening force, a coiling force, and a pressure of the watch band on a wrist of a user. 
     Clause 14: the one or more shape memory polymers is a composite comprising a Tm-type shape memory polymer and a Tg-type shape memory polymer. 
     As described above, one aspect of the present technology may include the gathering and use of data available from various sources. The present disclosure contemplates that in some instances, this gathered data may include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, twitter ID&#39;s, home addresses, data or records relating to a user&#39;s health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, or any other identifying or personal information. 
     The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For instance, health and fitness data may be used to provide insights into a user&#39;s general wellness, or may be used as positive feedback to individuals using technology to pursue wellness goals. 
     The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of or access to certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country. 
     Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, in the case of advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide mood-associated data for targeted content delivery services. In yet another example, users can select to limit the length of time mood-associated data is maintained or entirely prohibit the development of a baseline mood profile. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user may be notified upon downloading an app that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app. 
     Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user&#39;s privacy. De-identification may be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and/or other methods. 
     Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, content can be selected and delivered to users by inferring preferences based on non-personal information data or a bare minimum amount of personal information, such as the content being requested by the device associated with a user, other non-personal information available to the content delivery services, or publicly available information. 
     A reference to an element in the singular is not intended to mean one and only one unless specifically so stated, but rather one or more. For example, “a” module may refer to one or more modules. An element proceeded by “a,” “an,” “the,” or “said” does not, without further constraints, preclude the existence of additional same elements. 
     Headings and subheadings, if any, are used for convenience only and do not limit the invention. The word exemplary is used to mean serving as an example or illustration. To the extent that the term include, have, or the like is used, such term is intended to be inclusive in a manner similar to the term comprise as comprise is interpreted when employed as a transitional word in a claim. Relational terms such as first and second and the like may be used to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. 
     Phrases such as an aspect, the aspect, another aspect, some aspects, one or more aspects, an implementation, the implementation, another implementation, some implementations, one or more implementations, an embodiment, the embodiment, another embodiment, some embodiments, one or more embodiments, a configuration, the configuration, another configuration, some configurations, one or more configurations, the subject technology, the disclosure, the present disclosure, other variations thereof and alike are for convenience and do not imply that a disclosure relating to such phrase(s) is essential to the subject technology or that such disclosure applies to all configurations of the subject technology. A disclosure relating to such phrase(s) may apply to all configurations, or one or more configurations. A disclosure relating to such phrase(s) may provide one or more examples. A phrase such as an aspect or some aspects may refer to one or more aspects and vice versa, and this applies similarly to other foregoing phrases. 
     A phrase “at least one of” preceding a series of items, with the terms “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list. The phrase “at least one of” does not require selection of at least one item; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, each of the phrases “at least one of A, B, and C” or “at least one of A, B, or C” refers to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C. 
     It is understood that the specific order or hierarchy of steps, operations, or processes disclosed is an illustration of exemplary approaches. Unless explicitly stated otherwise, it is understood that the specific order or hierarchy of steps, operations, or processes may be performed in different order. Some of the steps, operations, or processes may be performed simultaneously. The accompanying method claims, if any, present elements of the various steps, operations or processes in a sample order, and are not meant to be limited to the specific order or hierarchy presented. These may be performed in serial, linearly, in parallel or in different order. It should be understood that the described instructions, operations, and systems can generally be integrated together in a single software/hardware product or packaged into multiple software/hardware products. 
     In one aspect, a term coupled or the like may refer to being directly coupled. In another aspect, a term coupled or the like may refer to being indirectly coupled. 
     Terms such as top, bottom, front, rear, side, horizontal, vertical, and the like refer to an arbitrary frame of reference, rather than to the ordinary gravitational frame of reference. Thus, such a term may extend upwardly, downwardly, diagonally, or horizontally in a gravitational frame of reference. 
     The disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. The disclosure provides various examples of the subject technology, and the subject technology is not limited to these examples. Various modifications to these aspects will be readily apparent to those skilled in the art, and the principles described herein may be applied to other aspects. 
     All structural and functional equivalents to the elements of the various aspects described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for”. 
     The title, background, brief description of the drawings, abstract, and drawings are hereby incorporated into the disclosure and are provided as illustrative examples of the disclosure, not as restrictive descriptions. It is submitted with the understanding that they will not be used to limit the scope or meaning of the claims. In addition, in the detailed description, it can be seen that the description provides illustrative examples and the various features are grouped together in various implementations for the purpose of streamlining the disclosure. The method of disclosure is not to be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, as the claims reflect, inventive subject matter lies in less than all features of a single disclosed configuration or operation. The claims are hereby incorporated into the detailed description, with each claim standing on its own as a separately claimed subject matter. 
     The claims are not intended to be limited to the aspects described herein, but are to be accorded the full scope consistent with the language of the claims and to encompass all legal equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirements of the applicable patent law, nor should they be interpreted in such a way.

Metadata:
Filing Date: 20200325
Publication Date: 20230103
Grant Date: 20230103
Priority Date: 20190926
Inventors: YOKOYAMA, YOSHIHIKO
YABE, OSAMU
SHIRAISHI, EIRYO
MATSUYUKI, NAOTO
Assignee: APPLE INC
CPC Classifications: [{"code": "A44C5/0053", "inventive": true, "first": true, "tree": "[]"}, {"code": "A44C5/0053", "inventive": true, "first": true, "tree": "[]"}, {"code": "A44C5/0053", "inventive": true, "first": true, "tree": "[]"}, {"code": "A44C27/008", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 84693036