Patent Publication Number: US-11394139-B2

Title: Thin-film connectors for data acquisition system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. patent application Ser. No. 16/734,729 filed Jan. 6, 2020, which claims the benefit of priority to U.S. Provisional Application No. 62/788,525, filed Jan. 4, 2019, the entire contents of which are incorporated by reference herein for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to data acquisition, and in particular to thin film connectors between a lead assembly and a data acquisition system. 
     BACKGROUND 
     Data acquisition (DAQ) is the process of measuring an electrical or physical phenomenon such as voltage, current, temperature, pressure, or sound with a computer. A DAQ system comprises sensors (e.g., recording electrodes), DAQ measurement hardware, and a computer with programmable software. Typically, the sensors are connected to the electronics (e.g., the hardware and software) via a lead assembly. The lead assembly is typically formed of a conductive material and takes the form of an insulated wire (e.g., a dedicated channel) connected to the sensors via a first connector on one end (e.g., a distal end) and the electronics of the via a second connector on another end (e.g., a proximal end). In some instances (e.g., deep implants), the lead assembly comprises additional conductors and connectors such as extension wires or a cable connected via connectors between the sensors and the electronics of the neurostimulator. 
     Conventional DAQ systems include between four and sixteen sensors or electrodes, and thus typically include four to sixteen channels or wires connected respectively to the sensors at the distal end and the electronics at the proximal end. However, there is a need for high density interfaces that include greater than sixteen sensors to interface with larger tissue volumes, to recruit smaller populations of neurons for recording. Increasing the density or number of sensors can increase the number of channels or wires needed to connect the sensors and the electronics of the DAQ systems. In order to implement high channel or wire counts, there is a need for reliable electrical connections that can maintain contact and electrical isolation in a subject body (e.g., a patient body). Standard connectors for DAQ systems either terminate with male pins or female solder cups. Direct soldering, welding or mechanical crimping with the male pins or female solder cups may work for low channel counts (e.g., bipolar or tripolar design), but become infeasible when there are much denser contacts. Therefore, there is a need for reliable connectors for lead assemblies having high density interfaces. 
     BRIEF SUMMARY 
     In various embodiments, a connector is provided that comprises: a button comprising: a housing comprising: a proximal end, a distal end, a cavity, and a base plate positioned in the cavity separating the proximal end and the distal end; and a plurality of conductive pins extending from the proximal end of the housing through the base plate, and extending into a portion of the cavity on the distal end of the housing. The connector further comprises a thin-film adapter comprising: a supporting structure comprising a main body and a cable. The main body is positioned within the portion of the cavity on the distal end of the housing. The thin-film adapter further comprises a plurality of bond pads formed on the main body, and a plurality of conductive traces formed on the cable and extending onto the main body. The one or more traces of the plurality of conductive traces terminate at each bond pad of the plurality of bond pads. The thin-film adapter further comprises a plurality of feedthroughs that pass through the plurality of bond pads and the main body. Each conductive pin of the plurality of conductive pins extends through a feedthrough of the plurality of conductive feedthroughs, and each conductive pin is in electrical connection with the one or more traces of the plurality of conductive traces via each bond pad of the plurality of bond pads. 
     In some embodiments, the supporting structure is comprised of one or more layers of dielectric material, and the dielectric material is polyimide, liquid crystal polymer, parylene, polyether ether ketone, or a combination thereof. In some embodiments, the plurality of conductive traces are comprised of one or more layers of conductive material, and the conductive material is platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. In some embodiments, the plurality of bond pads are comprised of one or more layers of conductive material, and the conductive material is gold (Au), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. 
     In some embodiments, the cable extends from the cavity to an environment exterior of the button In some embodiments, the main body of the supporting structure and the cable of the supporting structure are monolithic. In other embodiments, the main body of the supporting structure and the cable of the supporting structure are separate structures. 
     In some embodiments, the thin-film adapter further comprises pressure sensitive adhesive that attaches the main body to the base plate. 
     In some embodiments, the thin-film adapter further comprises a conductive epoxy disposed on a bottom of each conductive pin of the plurality of conductive pins and each bond pad of the plurality of bond pads, respectively, to electrically connect each conductive pin to a corresponding bond pad. 
     In some embodiments, the thin-film adapter further comprises an insulation layer formed over the main body of the supporting structure and at least a portion of each bond pad of the plurality of bond pads. 
     In some embodiments, the thin-film adapter further comprises a backfill layer formed over the main body of the supporting structure and fills a majority of a volume of the cavity of the housing. 
     In various embodiments, a connector is provided that comprises: a button comprising: a housing comprising: a proximal end, a distal end, a cavity, and a base plate positioned in the cavity separating the proximal end and the distal end; and a plurality of conductive pins extending from the proximal end of the housing through the base plate, and extending into a portion of the cavity on the distal end of the housing. The connector further comprises a thin-film adapter comprising: a supporting structure positioned within the portion of the cavity on the distal end of the housing; a plurality of bond pads formed on the supporting structure; a plurality of conductive feedthroughs that pass through the supporting structure and are electrically connected to the plurality of bond pads; and a cable comprising a plurality of conductive traces that are electrically connected with the plurality of bond pads. Each conductive pin of the plurality of conductive pins extends through a conductive feedthrough of the plurality of feedthroughs, and each conductive pin is in electrical connection with a trace of the plurality of conductive traces via a bond pad of the plurality of bond pads. 
     In some embodiments, the supporting structure is comprised of one or more layers of dielectric material, and the dielectric material is polyimide, liquid crystal polymer, parylene, polyether ether ketone, or a combination thereof. In some embodiments, the plurality of conductive traces are comprised of one or more layers of conductive material, and the conductive material is platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. In some embodiments, the plurality of bond pads are comprised of one or more layers of conductive material, and the conductive material is gold (Au), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. 
     In some embodiments, the cable extends from the cavity to an environment exterior of the button. In some embodiments, the supporting structure and the cable are monolithic. In other embodiments, the supporting structure and the cable are separate structures. 
     In some embodiments, the plurality of conductive traces are electrically connected with the plurality of bond pads via an anisotropic conductive film or anisotropic conductive paste. In some embodiments, a bond formed between each trace of the plurality of conductive traces and each bond pad of the plurality of bond pads is encapsulated in an insulator. Optionally, the insulator is silicone. 
     In some embodiments, the button further comprises a spring positioned over the supporting structure and the base plate within the portion of the cavity on the distal end of the housing; and a cap over a portion of the housing that holds the spring under compression within the portion of the cavity on the distal end of the housing, where the spring holds the supporting structure abutted against the base plate. Optionally, an outer diameter of the spring matches an inner diameter of the housing, and the spring is positioned in direct contact with the supporting structure. In certain embodiments, the adapter is removable from the button. 
     In various embodiments, a connector is provided that comprises: a button comprising: a housing comprising a proximal end, a distal end, and a base plate formed at the distal end; and a plurality of conductive cups formed on the base plate. The button further comprises: a thin-film adapter comprising: a supporting structure comprising a first side and a second side, where the second side abuts the base plate; a plurality of bond pads formed on the first side of the supporting structure; and a plurality of conductive bumps formed on the second side of the supporting structure. The plurality of conductive bumps are in contact with the plurality of conductive cups formed on the base plate, and electrically connect the plurality of conductive cups with the plurality of bond pads through conductive feedthroughs in the supporting structure. The thin-film adapter further comprises a cable comprising a plurality of conductive traces in electrical connection with the plurality of bond pads. Each conductive cup of the plurality of conductive cups is in electrical connection with a trace of the plurality of conductive traces via a bond pad of the plurality of bond pads. 
     In some embodiments, the supporting structure is comprised of one or more layers of dielectric material, and the dielectric material is polyimide, liquid crystal polymer, parylene, polyether ether ketone, or a combination thereof. In some embodiments, the plurality of conductive traces are comprised of one or more layers of conductive material, and the conductive material is platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. In some embodiments, the plurality of bond pads are comprised of one or more layers of conductive material, and the conductive material is gold (Au), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. 
     In some embodiments, the cable extends from the cavity to an environment exterior of the button. In some embodiments, the supporting structure and the cable are monolithic. In other embodiments, the supporting structure and the cable are separate structures. 
     In some embodiments, the cylindrical tube comprises: (i) the one or more layers of dielectric material, where the first layer of dielectric material defines an outer diameter of the cylindrical tube and the second layer of dielectric material defines an inner diameter of the tube; and (ii) a core that at least partially fills an interior of the cylindrical tube defined by the inner diameter. 
     In some embodiments, the plurality of conductive traces are electrically connected with the plurality of bond pads via an anisotropic conductive film or anisotropic conductive paste. In some embodiments, a bond formed between each trace of the plurality of conductive traces and each bond pad of the plurality of bond pads is encapsulated in an insulator. Optionally, the insulator is silicone. 
     In some embodiments, the button further comprises a flange positioned over the supporting structure and the base plate on the distal end of the housing, where the flange holds the supporting structure abutted against the base plate. In some embodiments, the adapter is removable from the button. 
     In various embodiments, a thin-film lead assembly is provided comprising: a cable comprising a proximal end, a distal end, a first supporting structure that extends from the proximal end to the distal end, and a first set of conductive traces formed on a portion of the first supporting structure; an electrode assembly formed on the first supporting structure at the distal end of the cable, where the electrode assembly comprises one or more electrodes in electrical connection with one or more conductive traces of the first set of conductive traces; and a connector comprising: (i) a button comprising a base plate and a plurality of conductive connectors on the base plate, and (ii) an adapter comprising a second supporting structure, a plurality of bond pads exposed on a surface of the second supporting structure and electrically connected to the plurality of conductive connectors, and a second set of conductive traces that terminate at the plurality of bond pads. Each trace from the second set of conductive traces terminates at a bond pad of the plurality of bond pads, and the second set of conductive traces of the adapter are in electrical contact with the first set of conductive traces. 
     In various embodiments, a data acquisition system is provided comprising: a measurement and control device comprising an electronics module; a cable comprising a proximal end, a distal end, a first supporting structure that extends from the proximal end to the distal end, and a first set of conductive traces formed on a portion of the first supporting structure; an electrode assembly formed on the first supporting structure at the distal end of the cable, where the electrode assembly comprises one or more electrodes in electrical connection with one or more conductive traces of the first set of conductive traces; and a connector comprising: (i) a button comprising a base plate and a plurality of conductive connectors on the base plate, and (ii) an adapter comprising a second supporting structure, a plurality of bond pads exposed on a surface of the second supporting structure and electrically connected to the plurality of conductive connectors, and a second set of conductive traces that terminate at the plurality of bond pads. Each trace from the second set of conductive traces terminates at a bond pad of the plurality of bond pads, the second set of conductive traces of the adapter are in electrical contact with the first set of conductive traces, and the connector electrically connects the first set of conductive traces to the electronics module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be better understood in view of the following non-limiting figures, in which: 
         FIG. 1  shows a DAQ system in accordance with various embodiments; 
         FIGS. 2A-2H  show a connector in accordance with various embodiments; 
         FIGS. 3A-3E  show an alternative connector in accordance with various embodiments; 
       and 
         FIGS. 4A-4G  show an alternative connector in accordance with various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     I. Introduction 
     The following disclosure describes proximal connectors compatible with standard DAQ connectors (e.g., head caps with skin buttons) for high density interfaces (e.g., neural interfaces) and methods of microfabricating the proximal connectors. As used herein, the term “proximal” or “proximal end” refers to a first end of the main body, while the term “distal” or “distal end” refers to a second end opposing the first end. For example, the proximal end may be an end of the main body, which is closest to the user, and the distal end may be an end of the main body, which is furthest from the user. The proximal connector may be fabricated using microfabricating techniques. In certain embodiments, the connector is fabricated as a monolithic structure. As used herein, the phrase “monolithic” refers to a device fabricated using a same layer of base material. 
     As used herein, the phrase “microfabrication” refers to the process of fabricating miniature structures on micrometer scales and smaller. The major concepts and principles of microfabrication are microlithography, doping, thin films, etching, bonding, and polishing. As used herein, the phrase “thin films” refers to a layer of material ranging from fractions of a nanometer (monolayer) to several micrometers in thickness (e.g., between a few nanometers to about 100 μm). Thin films may be deposited by applying a very thin film of material (e.g., between a few nanometers to about 100 urn) onto a substrate surface to be coated, or onto a previously deposited layer of thin film. In various embodiments, a thin film connector is provided comprising a base polymer body (e.g., a supporting structure) and at least one conductive trace formed on the base polymer body. As used herein, the term “high density interface(s)” refers to a interface that comprises at least sixteen electrodes (i.e., recording, sensing, stimulating, other types of electrodes, or combinations thereof). Although the connectors described herein include twelve pins as an example (which is a classic research tool used for preclinical studies), it should be understood that this concept is easily scalable for higher density channel counts (e.g., &gt;100) by using a customized connector with more pins and adjusting the design of the connector in accordance with various aspects disclosed herein. 
     DAQ systems that include intracranial electrodes placed in brain tissue, neural electrodes placed at extra axial locations, and deep brain electrodes placed in the thalamus electrically interface with neural tissue and record various neurological conditions (e.g., pressure, blood flow, neural activity, brain activity, etc.) through electrical monitoring such as electroencephalography (EEG). As described herein, conventional DAQ systems comprise electronics and a lead assembly containing between four and sixteen sensors or electrodes. There is a need for high-density lead assemblies that can significantly increase the number of sensors or electrodes in order to interface with larger tissue volume, to recruit smaller populations of neurons for recording. Microfabricated thin film neural interfaces have been proposed to significantly increase the number of sensors or electrodes. However, a challenge for microfabricated thin film neural interfaces and thin film lead technology is how to electrically connect the lead assembly to the electronics (which may be positioned outside of the subject&#39;s body). 
     To address these limitations and problems, proximal connectors of various embodiments disclosed herein enable connections with high density neural interfaces and are compatible with standard DAQ connectors such as head caps and skin buttons. One illustrative embodiment of the present disclosure is directed to a connector comprising a flexible adapter that is built monolithically with thin film lead body on the same polymer substrate. In some embodiments, the connector comprises: a button comprising: a housing comprising: a proximal end, a distal end, a cavity, and a base plate positioned in the cavity separating the proximal end and the distal end; and conductive pins extending from the proximal end of the housing through the base plate, and extending into a portion of the cavity on the distal end of the housing. The connector further comprises a thin-film adapter comprising: a supporting structure comprising a main body and a cable. The main body is positioned within the portion of the cavity on the distal end of the housing. The thin-film adapter further comprises bond pads formed on the main body, and a conductive traces formed on the cable and extending onto the main body. The conductive traces terminate at the bond pads. The thin-film adapter further comprises feedthroughs that pass through the bond pads and the main body. Each conductive pin extends through a feedthrough, and each conductive pin is in electrical connection with one or more conductive traces via a bond pad. 
     In other embodiments, a connector is provided that comprises: a button comprising: a housing comprising: a proximal end, a distal end, a cavity, and a base plate positioned in the cavity separating the proximal end and the distal end; and conductive pins extending from the proximal end of the housing through the base plate, and extending into a portion of the cavity on the distal end of the housing. The connector further comprises a thin-film adapter comprising: a supporting structure positioned within the portion of the cavity on the distal end of the housing; bond pads formed on the supporting structure; a conductive feedthroughs that pass through the supporting structure and are electrically connected to the bond pads; and a cable comprising conductive traces that are electrically connected with the bond pads. Each conductive pin extends through a conductive feedthrough, and each conductive pin is in electrical connection with a conductive trace via a bond pad. 
     In other embodiments, a connector is provided that comprises: a button comprising: a housing comprising a proximal end, a distal end, and a base plate formed at the distal end; and conductive cups formed on the base plate. The button further comprises: a thin-film adapter comprising: a supporting structure comprising a first side and a second side, where the second side abuts the base plate; bond pads formed on the first side of the supporting structure; and conductive bumps formed on the second side of the supporting structure. The conductive bumps are in contact with the conductive cups formed on the base plate, and electrically connect the conductive cups with the bond pads through conductive feedthroughs in the supporting structure. The thin-film adapter further comprises a cable comprising conductive traces in electrical connection with the bond pads. Each conductive cup is in electrical connection with a conductive trace of via a bond pad. 
     Advantageously, these approaches provide a connector, which has increased contact points, a smaller footprint, and greater design flexibility. More specifically, these approaches enable connectors with reliable, non-permanent connections between a lead assembly and a DAQ system. This solution is scalable to connecting many electrodes (e.g., greater than sixteen) using a multi flex chip, and thus enabling several monitoring and therapeutic opportunities. Furthermore even for applications where multiple electrodes are not required, various embodiments can be miniaturized to make the system minimally invasive, additionally may make invasive anatomies to become accessible (or navigable) due to the miniaturization. It should be understood that although data acquisition applications are provided as examples of some embodiments, this solution is applicable to all leads and devices that need electrodes/sensors that need to be attached to an electronic device or controller, e.g., a neurostimulator. 
     II. Data Acquisition Devices and Systems with a Lead Assembly 
       FIG. 1  shows a data acquisition (DAQ) system  100  in accordance with some aspects of the present invention. In various embodiments, the DAQ system  100  includes a computing device  105 , a cable  110 , a skin button connector  115 , and a lead assembly  120 . The computing device  105  (e.g., a data logger or a pulse generator (IPG)) may include a housing  125 , a connector  130 , a power source  135 , a communications device  140  (e.g., a WiFi antenna), and an electronics module  145  (i.e., hardware, software or a combination thereof). The housing  125  may be comprised of materials that are biocompatible such as bioceramics or bioglasses for radio frequency transparency, or metals such as titanium. In accordance with some aspects of the present invention, the size and shape of the housing  125  may be selected such that the computing device  105  can be attached to the exterior of a subject. In the example shown in  FIG. 1 , the connector  130  is attached to a hole in a surface of the housing  125  such that the housing  125  may be sealed. The connector  130  may include one or more contacts (i.e., electrically conductive elements, pins, wires, tabs, pads, etc.) mounted within the housing  125  or a cap extending from an interior to an exterior of the housing  125 . The power source  135  may be within the housing  125  and connected (e.g., electrically connected) to the electronics module  145  to power and operate the components of the electronics module  145 . The communications device  140  may be connected (e.g., electrically connected) to the electronics module  145  for wired or wireless communication with external devices via, for example, radiofrequency (RF) telemetry. 
     In some embodiments, the electronics module  145  may be connected (e.g., electrically connected) to interior ends of the connector  130  such that the electronics module  145  is able to sample or apply a signal or electrical current via conductive traces of the lead assembly  120  connected to the skin button connector  115 . As used herein, “conductive” refers to a material&#39;s or component&#39;s ability to conduct an electric current or electric signal. The electronics module  145  may include discrete and/or integrated electronic circuit components that implement analog and/or digital circuits capable of producing the functions attributed to the data acquisition devices or systems such as sampling signals that measure real world physical conditions and converting the resulting samples into digital numeric values that can be manipulated by a computer. In various embodiments, the electronics module  145  may include software and/or electronic circuit components such as signal conditioning circuitry  150  that converts sensor signals into a form that can be converted to digital values, a controller  155  that determines or senses electrical activity and physiological responses via the electrodes and sensors, an optional  160  analog-to-digital converters to convert conditioned sensor signals to digital values, and a memory  165  with program instructions operable on by the controller  155  to perform one or more processes for sampling or recording signals. In some embodiments, one or more data acquisition applications stored in memory  165  are controlled via controller  155  using software programs, which may be developed by various general purpose programming languages such as Assembly, BASIC, C, C++, C#, Fortran, Java, LabVIEW, Lisp, Pascal, etc. 
     In various embodiments, the wiring assembly  110  is an assembly of electrical cables, wires, or thin-film conductive traces, which sample signals, transmit signals, transmit electrical power, or a combination thereof, between computing device  105  and lead assembly  120  via the skin button connector  115 . The skin button connector  115  is a male connector comprising conductive pins and a cap or a female connector comprising conductive cups and a cap. In some embodiments, the skin button connector  115  is attached to a subject such that the lead assembly may be implanted within the subject while maintaining electrical connection with the wiring assembly  110  and computing device  105 , which may be position outside of the subject. For example, the skin button connector  115  may traverse the skin and/or bone layer of a subject. In some embodiments, the skin button connector  115  is configured as a temporary connector such that the wiring assembly  110  and/or lead assembly  120  may be removably plugged into and detached from the skin button connector. A used herein, “electrically connected”, “electrical connection”, “electrical coupling”, “electrical contact”, and the like, mean that the two or more components are connected in a manner to complete a circuit affecting electrical current or signal transmission. 
     In various embodiments, the lead assembly  120  includes a cable or lead body  170 , one or more electrode assemblies  175  having one or more electrodes  180  (e.g., one or more sensors), and a connector  185 . In some embodiments, the lead assembly  120  is a monolithic structure. In various embodiments, the connector  185  includes skin button connector  115  and a thin-film adapter  190  comprising: (i) a supporting structure, (ii) a plurality of bond pads, (iii) a plurality of conductive traces terminating at the plurality of bond pads, and (iv) a plurality of feedthroughs or vias connecting the plurality of bond pads to the conductive pins or cups of the skin button connector  115 . The cable  170  may include one or more conductive traces  195  formed on a supporting structure. In some embodiments, the supporting structure of the cable  170  is the same supporting structure of the adapter  190 , and thus the components are monolithic. In other embodiments, the supporting structure of the cable  170  is different from the supporting structure of the adapter  190 . 
     The one or more conductive traces  195  of the cable  170  allow for electrical coupling of the computing device  105  to the electrodes and/or sensors  180  of the electrode assemblies  175  via the connector  185 . In some embodiments, the one or more of conductive traces  195  of the cable  170  are the same conductive traces as the plurality of conductive traces of the connector  185  (monolithic traces). In other embodiments, the one or more of conductive traces  195  of the cable  170  are different conductive traces from the plurality of conductive traces of the connector  185  (a different structure but electrically connected). As described herein in detail, the supporting structure may be formed with a dielectric material such as a polymer having suitable dielectric, flexibility and biocompatibility characteristics. Polyurethane, polycarbonate, silicone, polyethylene, fluoropolymer and/or other medical polymers, copolymers and combinations or blends may be used. The conductive material for the traces may be any suitable conductor such as stainless steel, silver, copper or other conductive materials, which may have separate coatings or sheathing for anticorrosive, insulative and/or protective reasons. 
     The electrode assemblies  175  may include the electrodes and/or sensors  180  fabricated using various shapes and patterns to create certain types of electrode assemblies (e.g., book electrodes, split cuff electrodes, spiral cuff electrodes, epidural electrodes, helical electrodes, probe electrodes, linear electrodes, neural probe, paddle electrodes, intraneural electrodes, etc.). In various embodiments, the electrode assemblies  175  include a base material that provides support for microelectronic structures including the electrodes  180 , a wiring layer, optional contacts, etc. In some embodiments, the base material is the supporting structure. The wiring layer may be embedded within or located on a surface of the supporting structure. The wiring layer may be used to electrically connect the electrodes  180  with the one or more conductive traces directly or indirectly via a lead conductor. The term “directly”, as used herein, may be defined as being without something in between. The term “indirectly”, as used herein, may be defined as having something in between. In some embodiments, the electrodes  195  may make electrical contact with the wiring layer by using the contacts. 
     III. Thin-Film Connectors and Fabrication Thereof 
       FIGS. 2A-2H  show a thin-film connector  200  (e.g., the connector  185  described with respect to  FIG. 1 ) in accordance with aspects of the present disclosure. In various embodiments, the thin-film connector  200  comprises a button  205  comprising a housing  210  having a proximal end  215 , a distal end  220 , a cavity  225 , and a base plate  230  position in the cavity  225  separating the proximal end  215  and the distal end  220 . As shown in  FIGS. 2A and 2E , the button  205  may be a male button (i.e., presence of conductor pins) with a first portion (a) configured to attach with a second portion (b) that has structure(s) such as a flange for attaching the button  205  to a subject (e.g., a patient). The housing  210  may be comprised of materials that are biocompatible such as bioceramics or bioglasses, or metals such as copper, gold, titanium. In accordance with some aspects, the size and shape of the housing  210  may be selected such that a wiring may traverse via the connector from the exterior of a subject through a layer such as a skin or bone layer into the interior of the subject. In some embodiments, the button  205  further comprises a plurality of conductive pins  235  extending from the proximal end  215  of the housing  210  through the base plate  230 , and extending into a portion of the cavity  225  on the distal end  220  of the housing  210 . The base plate  230  may be made of an insulator such as a polymer or dielectric material. 
     As shown in  FIGS. 2D and 2F , the thin-film connector  200  may further comprise a thin-film adapter  240 . In various embodiments, the thin-film adapter  240  comprises a supporting structure  245  comprising a main body  250  and a cable  255 . In some embodiments, the thin-film adapter  240  is built monolithically with the thin-film lead body (e.g., the lead body  170  discussed with respect to  FIG. 1 ) on a same polymer substrate, e.g., supporting structure  245 . The supporting structure  245  may be comprised of one or more layers of dielectric material. In some embodiments, the dielectric material is a polymer such as a polymer of imide monomers (i.e., a polyimide), a liquid crystal polymer (LCP) such as Kevlar®, parylene, polyether ether ketone (PEEK), or combinations thereof. In certain embodiments, the dielectric material is polyimide, LCP, parylene, PEEK, or a combination thereof. As shown in  FIGS. 2B, 2C, 2G, and 2H , the main body  250  may be positioned within the portion of the cavity  225  on the distal end  220  of the housing  210 . As shown in  FIG. 2D , the main body  250  may be patterned into a particular shape such as a circle to fit inside of the cavity  225  of the button  205 . During assembling as shown in  FIGS. 2B and 2C , the main body  250  may be pushed into the cavity  225  of the skin button  205 . In some embodiments, the cable  255  extends from the cavity  225  to an environment exterior of the button  205  (e.g., an environment inside a subject or outside of a subject). In some embodiments, the main body  250  of the supporting structure  245  and the cable  255  of the supporting structure  245  are monolithic. As shown in  FIGS. 2F-2H , the thin-film adapter  240  may further comprises pressure sensitive adhesive  260  that attaches the main body  250  to the base plate  230  when the main body  250  is pushed into the cavity  225  of the skin button  205 . As such, in certain embodiments, the thin-film adapter  240  is not removable from the button  205  once assembled. 
     As shown in  FIGS. 2D and 2F-2H , the thin-film adapter  240  may further comprise a plurality of bond pads  265  formed on the main body  250 . In some embodiments, the bond pads  265  are comprised of one or more layers of conductive material. In certain embodiments, the conductive material is gold (Au), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. A shown in  FIGS. 2F-2H , the thin-film adapter  240  may further comprise an insulation layer  270  formed over the main body  250  of the supporting structure  245  and at least a portion  275  of one or more bond pads of the plurality of bond pads  265 . In some embodiments, the insulation layer  270  comprises one or more layers of polymer or dielectric. As shown in  FIG. 2D , the thin-film adapter  240  may further comprise a plurality of conductive traces  280  formed on the cable  255  and extending onto the main body  250 . In some embodiments, the plurality of conductive traces  280  terminate at the plurality of bond pads  265 . In certain embodiments, each trace from the plurality of conductive traces  280  terminates at a bond pad from the plurality of bond pads  265 . In other embodiments, one or more traces from the plurality of conductive traces  280  terminate at each bond pad from the plurality of bond pads  265 . In other embodiments, each trace from the plurality of conductive traces  280  terminates at a corresponding bond pad from the plurality of bond pads  265  such that there is a one to one relationship between the traces and the bond pads. In some embodiments, the plurality of conductive traces  280  are comprised of one or more layers of conductive material. In certain embodiments, the conductive material is platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. 
     As shown in  FIGS. 2D and 2F-2H , the thin-film adapter  240  may further comprise a plurality of feedthroughs  285  that pass through the plurality of bond pads  265  and the main body  250 . In some embodiments, each conductive pin of the plurality of conductive pins  235  extends through a feedthrough of the plurality of feedthroughs  285 , and each conductive pin is in electrical connection with the one or more traces of the plurality of conductive traces  280  via each bond pad of the plurality of bond pads  265 . As shown in  FIGS. 2G and 2H , a conductive epoxy  290  may be disposed on a bottom of each conductive pin of the plurality of conductive pins  235  and each bond pad of the plurality of bond pads  265 , respectively, to electrically connect each conductive pin to a corresponding bond pad. The conductive epoxy  290  may be dispensed using a dispensing needle (d) onto the bottom of each conductive pin to form electrical connection between the conductive pins  235  and the bond pads  265 . In some embodiments. A digital dispenser is used to accurately control epoxy droplet&#39;s volume to prevent shorts. As shown in  FIG. 2H , a backfill layer  295  may be formed over the main body  250  of the supporting structure  245  and fills a majority of a volume of the cavity  225  of the housing  210 . For example, after curing the conductive epoxy  290 , a non-conductive material such as silicone may be backfilled into a majority of a volume of the cavity  225  in order to reinforce the bonds and work as a strain relief for the cable  255 . A used herein, a “majority” is the greater part, or more than half, of the total. For example, a majority may be a subset of the total volume of the cavity  225  after the conductive pins and adapter are disposed in the cavity, and the subset consists of more than half of the total volume. 
       FIGS. 3A-3E  show an alternative thin-film connector  300  (e.g., the connector  185  described with respect to  FIG. 1 ) in accordance with aspects of the present disclosure. In various embodiments, the thin-film connector  300  comprises a button  305  comprising a housing  310  having a proximal end  315 , a distal end  320 , a cavity  325 , and a base plate  330  position in the cavity  325  separating the proximal end  315  and the distal end  320 . As shown in  FIG. 3B  (and as described with respect to  FIG. 2A ), the button  305  may be a male button (i.e., presence of conductor pins) with a first portion (a) configured to attach with a second portion (b) that has structure(s) such as a flange for attaching the button  305  to a subject (e.g., a patient). The housing  310  may be comprised of materials that are biocompatible such as bioceramics or bioglasses, or metals such as copper, gold, titanium. In accordance with some aspects, the size and shape of the housing  310  may be selected such that a wiring may traverse via the connector from the exterior of a subject through a layer such as a skin or bone layer into the interior of the subject. In some embodiments, the button  305  further comprises a plurality of conductive pins  335  extending from the proximal end  315  of the housing  310  through the base plate  330 , and extending into a portion of the cavity  325  on the distal end  320  of the housing  310 . The base plate  330  may be made of an insulator such as a polymer or dielectric material. 
     As shown in  FIGS. 3A and 3C-3E , the thin-film connector  300  may further comprise a thin-film adapter  340 . In various embodiments, the thin-film adapter  340  comprises a supporting structure  345 . The supporting structure  345  may be comprised of one or more layers of dielectric material. In some embodiments, the dielectric material is a polymer such as a polymer of imide monomers (i.e., a polyimide), a LCP, parylene, PEEK, or combinations thereof. In certain embodiments, the dielectric material is polyimide, LCP, parylene, PEEK, or a combination thereof. As shown in  FIGS. 3D and 3E , the supporting structure  345  may be positioned within the portion of the cavity  325  on the distal end  320  of the housing  310 . For example, during assembling as described with respect to  FIGS. 2B and 2C , the supporting structure  345  may be pushed into the cavity  325  of the skin button  305 . As shown in  FIG. 3A , the supporting structure  345  may be patterned into a particular shape such as a circle to fit inside of the cavity  325  of the button  305 . 
     As shown in  FIGS. 3A and 3C-3E , the thin-film adapter  340  may further comprise a plurality of bond pads  350  formed on the supporting structure  345 . In some embodiments, the bond pads  350  are comprised of one or more layers of conductive material. In certain embodiments, the conductive material is gold (Au), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. A shown in  FIGS. 3A and 3C-3E , the thin-film adapter  340  may further comprise a plurality of conductive feedthroughs  355  that pass through the supporting structure  345  and are electrically connected to the plurality of bond pads  350 . In some embodiments, the conductive feedthroughs  355  are comprised of a via  357  and one or more layers of conductive material  358 . The vias  357  may be lined with one or more layers of the conductive material  358 . In certain embodiments, the conductive material  358  is gold (Au), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. The plurality of conductive feedthroughs  355  may be electrically connected to the plurality of bond pads  350  by direct contact or indirect contact, for example, by way of one or more conductive traces  360 . 
     As shown in  FIGS. 3C-3E , the thin-film adapter  340  may further comprise a cable  365  comprising a plurality of conductive traces  370  (see also in  FIG. 2D  with respect to cable  255  and conductive traces  280 ) that are electrically connected with the plurality of bond pads  350 . The cable  365  may extend from the cavity  325  to an environment exterior of the button  305 . In some embodiments, the cable  365  is built monolithically with the thin-film lead body (e.g., the lead body  170  discussed with respect to  FIG. 1 ) on a same polymer substrate, e.g., supporting structure. In some embodiments, the supporting structure  345  and the cable  365  are monolithic, as described with respect to  FIGS. 2B-2H . In other embodiments, the supporting structure  345  and the cable  365  are separate structures. As shown in  FIGS. 3C-3E , when the supporting structure  345  and the cable  365  are separate structures, the plurality of conductive traces  370  may be electrically connected with the plurality of bond pads  350  via an anisotropic conductive film or anisotropic conductive paste  375 . In some embodiments, a bond formed between each trace of the plurality of conductive traces  370  and each bond pad of the plurality of bond pads  350  is encapsulated in an insulator  380 . In certain embodiments, the insulator  380  is a polymer such as silicone. 
     In some embodiments, the plurality of conductive traces  370  terminate at the plurality of bond pads  350 . In certain embodiments, each trace from the plurality of conductive traces  370  terminates at a bond pad from the plurality of bond pads  350 . In other embodiments, one or more traces from the plurality of conductive traces  370  terminate at each bond pad from the plurality of bond pads  350 . In other embodiments, each trace from the plurality of conductive traces  370  terminates at a corresponding bond pad from the plurality of bond pads  350  such that there is a one to one relationship between the traces and the bond pads. In some embodiments, the plurality of conductive traces  370  are comprised of one or more layers of conductive material. In certain embodiments, the conductive material is platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. As shown in  FIGS. 3D and 3E , each conductive pin of the plurality of conductive pins  335  extends through a conductive feedthrough of the plurality of feedthroughs  355 , and each conductive pin is in electrical connection with a trace of the plurality of conductive traces  370  via a bond pad of the plurality of bond pads  350 . 
     As shown in  FIG. 3E , the button  305  may further comprise a spring  385  positioned over the supporting structure  345  and the base plate  330  within the portion of the cavity  325  on the distal end  320  of the housing  310 . In some embodiments, a cap  390  is provided over a portion of the housing  310  that holds the spring  385  under compression within the portion of the cavity  325  on the distal end  320  of the housing. As such, the spring  385  holds the supporting structure  345  abutted against the base plate  330 , and the thin-film adapter  340  is removable from the button  305  once assembled (after removal of the cap  390  and spring  385 ). In some embodiments, an outer diameter of the spring  385  matches an inner diameter of the housing  310 . In some embodiments, the spring  385  is positioned in direct contact with the supporting structure  345 . In other embodiments, the spring  385  is positioned in indirect contact with the supporting structure  345 , for example, an insulator layer may be disposed between the spring  385  and the supporting structure  345 . 
       FIGS. 4A-4G  show an alternative thin-film connector  400  (e.g., the connector  185  described with respect to  FIG. 1 ) in accordance with aspects of the present disclosure. In various embodiments, the thin-film connector  400  comprises a button  405  comprising a housing  410  having a proximal end  415 , a distal end  420 , and a base plate  425  formed at the distal end  420 . As shown in  FIGS. 4A and 4D , the button  405  may be a female button (i.e., presence of conductor cups or solder cups) with a first portion (a) configured to attach with a second portion (b) that has structure(s) such as a flange for attaching the button  405  to a subject (e.g., a patient). The housing  410  may be comprised of materials that are biocompatible such as bioceramics or bioglasses, or metals such as copper, gold, titanium. In accordance with some aspects, the size and shape of the housing  410  may be selected such that a wiring may traverse via the connector from the exterior of a subject through a layer such as a skin or bone layer into the interior of the subject. In some embodiments, the button  405  further comprises a plurality of conductive cups or solder cups  430  formed on the base plate  425 . The conductive cups  430  may comprise holes or vias  435  extending from the proximal end  415  of the housing  410  through the base plate  425  to the distal end  420  of the housing  410 . The base plate  425  may be made of an insulator such as a polymer or dielectric material. 
     As shown in  FIGS. 4B, 4C, and 4E-4G , the thin-film connector  400  may further comprise a thin-film adapter  440 . In various embodiments, the thin-film adapter  440  comprises a supporting structure  445 . As shown in  FIGS. 4B and 4C , the supporting structure  445  may comprise a first side  450  and a second side  455 . The supporting structure  445  may be comprised of one or more layers of dielectric material. In some embodiments, the dielectric material is a polymer such as a polymer of imide monomers (i.e., a polyimide), a LCP, parylene, PEEK, or combinations thereof. In certain embodiments, the dielectric material is polyimide, LCP, parylene, PEEK, or a combination thereof. As shown in  FIGS. 4F and 4G , the supporting structure  445  may be positioned abutting the base plate  425  on the distal end  420  of the housing  410 . For example, during assembling, the supporting structure  445  may be placed abutting the base plate  425  to make contact with the conductive cups  430 . As shown in  FIGS. 4B and 4C , the supporting structure  445  may be patterned into a particular shape such as a circle to fit on top of the base plate  425  of the button  405 . 
     As shown in  FIGS. 4B and 4E-4G , the thin-film adapter  440  may further comprise a plurality of bond pads  460  formed on the supporting structure  445 . The plurality of bond pads  460  may be formed on the first side  450  of the supporting structure. In some embodiments, the bond pads  460  are comprised of one or more layers of conductive material. In certain embodiments, the conductive material is gold (Au), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. A shown in  FIGS. 4B and 4E-4G , the thin-film adapter  440  may further comprise a plurality of conductive feedthroughs  465  that pass through the supporting structure  445  and are electrically connected to the plurality of bond pads  460 . In some embodiments, the conductive feedthroughs  465  are comprised of a via  467  and one or more layers of conductive material  468 . The vias  467  may be lined with one or more layers of the conductive material  468 . In certain embodiments, the conductive material  468  is gold (Au), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. The plurality of conductive feedthroughs  465  may be electrically connected to the plurality of bond pads  460  by direct contact or indirect contact, for example, by way of one or more conductive traces  470 . 
     As shown in  FIGS. 4C and 4E-4G , the thin-film adapter  440  may further comprise a plurality of conductive bumps  475  formed on the second side  455  of the supporting structure  445 . In some embodiments, the plurality of conductive bumps  475  are in contact with the plurality of solder cups  430  formed on the base plate  425 , and electrically connect the plurality of solder cups  430  with the plurality of bond pads  460  through conductive feedthroughs  465  in the supporting structure  445 . For example, on the second side  455  a conductive paste such as solder paste may be screen printed and then reflowed to form semi-hemispheric conductive bumps  475 . The conductive bumps  475  are connected to bond pads  460  on the first side  450  of the supporting structure  445  through the metallized vias  467 . In some embodiments, the conductive bumps  475  are comprised of conductive material or solder. In certain embodiments, the conductive material is tin (Sn), lead (Pb), zinc (Zn), cadmium (Cd), silver (Ag), bismuth (Bi), or any alloy thereof. 
     As shown in  FIGS. 4E-4F , the thin-film adapter  440  may further comprise a cable  480  comprising a plurality of conductive traces  485  (see also in  FIG. 2D  with respect to cable  255  and conductive traces  280 ) that are electrically connected with the plurality of bond pads  460 . The cable  480  may extend from the base plate  425  to an environment exterior of the button  405 . In some embodiments, the cable  480  is built monolithically with the thin-film lead body (e.g., the lead body  170  discussed with respect to  FIG. 1 ) on a same polymer substrate, e.g., supporting structure. In some embodiments, the supporting structure  445  and the cable  480  are monolithic, as described with respect to  FIGS. 2B-2H . In other embodiments, the supporting structure  445  and the cable  480  are separate structures. As shown in  FIGS. 4E-4G , when the supporting structure  445  and the cable  480  are separate structures, the plurality of conductive traces  485  may be electrically connected with the plurality of bond pads  460  via an anisotropic conductive film or anisotropic conductive paste  490 . In some embodiments, a bond formed between each trace of the plurality of conductive traces  485  and each bond pad of the plurality of bond pads  460  is encapsulated in an insulator  492 . In certain embodiments, the insulator  492  is a polymer such as silicone. 
     In some embodiments, the plurality of conductive traces  485  terminate at the plurality of bond pads  460 . In certain embodiments, each trace from the plurality of conductive traces  485  terminates at a bond pad from the plurality of bond pads  460 . In other embodiments, one or more traces from the plurality of conductive traces  485  terminate at each bond pad from the plurality of bond pads  460 . In other embodiments, each trace from the plurality of conductive traces  485  terminates at a corresponding bond pad from the plurality of bond pads  460  such that there is a one to one relationship between the traces and the bond pads. In some embodiments, the plurality of conductive traces  485  are comprised of one or more layers of conductive material. In certain embodiments, the conductive material is platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof. As shown in  FIGS. 4F and 4G , each conductive cup of the plurality of conductive cups  430  is in electrical connection with a trace of the plurality of conductive traces  485  via a bond pad of the plurality of bond pads  460 . 
     As shown in  FIG. 4G , the button  405  may further comprise cap having a flange  495  positioned over the supporting structure  445  and the base plate  425  on the distal end  420  of the housing  410 . As such, the flange  495  holds the supporting structure  445  abutted against the base plate  425 , and the thin-film adapter  440  is removable from the button  405  once assembled (after removal of the cap and flange  495 ). In some embodiments, the flange  495  is positioned in direct contact with the supporting structure  445 . In other embodiments, the flange  495  is positioned in indirect contact with the supporting structure  445 , for example, an insulator layer may be disposed between the flange  495  and the supporting structure  445 . 
     While the invention has been described in detail, modifications within the spirit and scope of the invention will be readily apparent to the skilled artisan. It should be understood that aspects of the invention and portions of various embodiments and various features recited above and/or in the appended claims may be combined or interchanged either in whole or in part. In the foregoing descriptions of the various embodiments, those embodiments which refer to another embodiment may be appropriately combined with other embodiments as will be appreciated by the skilled artisan. Furthermore, the skilled artisan will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention.