Patent ID: 12247847

While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION

It should also be understood that, as used herein, the terms “vertical,” “horizontal,” “lateral,” “upper,” “lower,” “left,” “right,” “inner,” “outer,” etc., can refer to relative directions or positions of features in the disclosed devices and/or assemblies shown in the Figures. For example, “upper” or “uppermost” can refer to a feature positioned closer to the top of a page than another feature. These terms, however, should be construed broadly to include devices and/or assemblies having other orientations, such as inverted or inclined orientations where top/bottom, over/under, above/below, up/down, and left/right can be interchanged depending on the orientation.

FIGS.1A-Dare schematic illustrations of a compliant sensor system showing a simplified two-electrode stack in accordance with disclosed embodiments.FIG.1Aillustrates a top electrode layer2that may comprise an elastomeric layer (e.g., silicone) with conductive particles (e.g., nano-particles, such as carbon black, nickel nano-strands, silver nano-particles, graphene nano-platelets, graphene-oxides, or the like) integrated within. While shown inFIG.1Aas a continuous layer, top electrode layer2may also be “hatched” as disclosed below with reference toFIGS.3-6. Top electrode layer2may also include a PCB interface104and a number of conductive trace pads106for attaching a PCB, sensor traces, or other electronics, for operation and control of the sensor system.

FIG.1Bshows a dielectric layer12that may comprise an elastomeric material (e.g., silicone) and, as desired, may have some conductive material integrated within depending upon, among other things, the intended amount of permittivity, or the like. While not drawn rigorously to scale, dielectric layer12is sized to be slightly smaller than top electrode layer2to leave a perimeter edge of top electrode layer2uncovered by dielectric layer12and allow electrical contact with perimeter electrode140as disclosed below. Embodiments of dielectric layer12may also include a tab portion114sized to cover PCB interface104up to the trace pads106.

FIG.1Cshows a signal electrode layer16which may comprise an elastomeric material (e.g., silicone) with conductive material (e.g., nano-particles, such as carbon black, nickel nano-strands, silver nano-particles, graphene nano-platelets, graphene-oxides, or the like) confined to the sensor regions118, traces120, and perimeter electrode140. As shown, a number of sensor regions118may be distributed throughout the layer116. Sensor regions118may comprise regions of electrically conductive material. Sensor regions118are electrically in communication with traces120that are printed with signal electrode layer16. Traces120terminate at a tab region122that aligns with trace pads106to provide electrical connection points for traces120. As shown, embodiments of signal electrode layer16may include a perimeter electrode140that electrically connects to top electrode layer2to, among other things, provide electrical isolation for the entire sensor system.

FIG.1Dis a schematic cross-sectional view of a stack100of the above-disclosed layers to form a compliant sensor system. As shown, top electrode layer2, is in between dielectric layer12and signal electrode layer16. As also indicated schematically, perimeter electrode140electrically connects top electrode layer2and signal electrode layer16. Other configurations are also possible.

FIGS.2A-Gare illustrations of electrode and shielding systems for a flexible three-electrode stack sensor system in accordance with disclosed embodiments. As shown inFIG.2A, a first cover dielectric layer108may optionally be provided in some embodiments. First cover dielectric layer108may comprise an elastomeric material such as silicone, or the like. First cover dielectric layer108may be used to cover top electrode layer102(disclosed below withFIG.2B) to prevent the top electrode layer102from unwanted contact with other objects, surfaces, or the like. While not drawn rigorously to scale, first cover dielectric layer108is sized to cover top electrode layer102and may be larger than top electrode layer102in some embodiments. As also indicated, first cover dielectric layer108includes a tab portion110for covering top electrode layer102up to conductive trace pads106.

FIG.2Bshows a top electrode layer102that may be provided. Top electrode layer102can comprise an elastomeric layer (e.g., silicone) with conductive particles (e.g., nano-particles, such as carbon black, nickel nano-strands, graphene nano-platelets, graphene-oxides, or the like) integrated within. Top electrode layer102may also include a PCB interface104and a number of conductive trace pads106for attaching a PCB, sensor traces, or other electronics, for operation and control of the sensor system.

FIG.2Cshows a second dielectric, layer112. Second dielectric layer112may comprise an elastomeric material (e.g., silicone) and, as desired, may have some conductive material integrated within depending upon, among other things, the intended amount of permittivity, or the like. While not drawn rigorously to scale, second dielectric layer112is sized to be slightly smaller than top electrode layer102to leave a perimeter edge of top electrode layer102uncovered by dielectric layer112and allow electrical contact with perimeter electrode140as disclosed herein. Embodiments of second dielectric layer112may also include a tab portion114sized to cover PCB interface104up to the trace pads106.

FIG.2Dshows a signal electrode layer116. Embodiments of signal electrode layer116may comprise an elastomeric material (e.g., silicone) with conductive material (e.g., nano-particles, such as carbon black, nickel nano-strands, silver nano-particles, graphene nano-platelets, graphene-oxides, or the like) confined to the sensor regions118, traces120, and perimeter electrode140. As shown, a number of sensor regions118may be distributed throughout the layer116. Sensor regions118may comprise regions of electrically conductive material. Sensor regions118are electrically in communication with traces120that are printed with signal electrode layer116. Traces120terminate at a tab region122that aligns with trace pads106to provide electrical connection points for traces120. As shown, embodiments of signal electrode layer116may include a perimeter electrode140that electrically connects to top electrode layer102and bottom electrode layer132to, among other things, provide electrical isolation for the entire sensor system.

FIG.2Eshows a third dielectric, layer124. Third dielectric layer124may comprise an elastomeric material (e.g., silicone) and, as desired, may have some conductive material integrated within depending upon, among other things, the intended amount of permittivity, or the like. While not drawn rigorously to scale, third dielectric layer124is sized to be slightly smaller than bottom electrode layer132to leave a perimeter edge of bottom electrode layer132uncovered by third dielectric layer124and allow electrical contact with perimeter electrode140as disclosed herein. Embodiments of third dielectric layer124may also include a tab portion126sized to cover PCB interface104up to the trace pads106.

FIG.2Fshows a bottom electrode layer132that may be provided. Bottom electrode layer132can comprise an elastomeric layer (e.g., silicone) with conductive particles (e.g., nano-particles, such as carbon black, nickel nano-strands, graphene nano-platelets, graphene-oxides, or the like) integrated within. As also indicated, bottom electrode layer132includes a tab portion134for, among other things, providing mechanical strength for the connective region (e.g., PCB interface104) for the trace pads106to be printed onto, as opposed to tab portions110,114which are pulled back as to not cover the electrically conductive pads106. Other configurations are also possible.

FIG.2Gshows a second cover dielectric layer128that may optionally be provided in some embodiments. Second cover dielectric layer128may comprise an elastomeric material such as silicone, or the like. Second cover dielectric layer128may be used to cover bottom electrode layer132(disclosed above withFIG.2F) to prevent the bottom electrode layer132from unwanted contact with other objects, surfaces, or the like. While not drawn rigorously to scale, second cover dielectric layer128is sized to cover bottom electrode layer132and may be larger than bottom electrode layer132in some embodiments. As also indicated, second cover dielectric layer128includes a tab portion130for supporting the connective region (e.g., PCB interface104) for the trace pads106.

As persons of ordinary skill in the art having the benefit of this disclosure would understand, the three electrode stack shown inFIGS.2A-Gmay be extended to more, or less, electrode layers. Likewise, more or less sensor regions118and traces120may be used in other configurations and shapes.

FIG.3is a schematic illustration for a top electrode layer202in accordance with disclosed embodiments. As shown, top electrode layer202includes a partially open, checkered, or hatched portion208of an electrically conducting material such as carbon nanotubes, silver nanoparticles, other conductive particles, or the like, that is printed on a elastomeric substrate (e.g., silicone or the like). One advantage of the hatched portion208is that it provides similar electric shielding for a capacitive sensor with a reduced stray capacitance from the traces (e.g.,120) due to the reduced surface area of the traces coupling to the top (e.g.,102,202) and bottom (e.g.,132,432) electrodes. Such a configuration results in less error signal generated by strain and or flexion in the traces. The reduction of the error signal is proportional to the amount of surface area that is removed by the hatched portion208. Embodiments of the hatched portion208may vary the open space amounts according to, among other things, the signal frequencies to be shielded, the width of the traces120, and the like. In general, wider traces120produce more error signal (mechanical crosstalk) and for those embodiments a more aggressive hatching portion208(i.e., larger voids) will further reduce the crosstalk.

As also shown, top layer202may include a PCB interface204and a number of conductive trace pads206for attaching a PCB, sensor traces, or other electronics, for operation and control of the sensor system. Sensing regions210A-210E are located in areas to align with sensing electrodes318A-318E on an electrode layer316(e.g., as shown inFIG.4). Of course, those of ordinary skill in the art having the benefit of this disclosure would understand that the shapes, sizes, connections, and locations of sensing regions210A-210E are merely exemplary and can vary in accordance with, among other things, the particular application of the sensor system.

FIG.4is a schematic illustration of a signal electrode layer316in accordance with disclosed embodiments. As shown, a number of sensing electrodes318A-318E that are printed with signal electrode layer316at the desired sizes, locations, and shapes. Sensing electrodes318A-318E are electrically connected to conductor traces320A-320E which may also vary in number, size, shape, location, and the like, as desired. Traces320A-320E terminate at a tab portion322that aligns with trace pads206to provide electrical connection points for traces320A-320E. As also shown, embodiments of signal electrode layer316may include a perimeter electrode340that electrically connects to top electrode layer202(and in some embodiments a bottom electrode layer (e.g.,132,432)) to, among other things, provide electrical isolation for the entire sensor system.

FIG.5is a schematic illustration of a bottom electrode layer432in accordance with disclosed embodiments. As shown, bottom electrode layer432includes a partially open, checkered, or hatched portion408of an electrically conducting material such as carbon nanotubes, silver nanoparticles, other conductive particles, or the like, that is printed on a elastomeric substrate (e.g., silicone or the like). One advantage of the hatched portion408is that it provides similar electric shielding for a capacitive sensor with a reduced stray capacitance from the traces (e.g.,120) due to the reduced surface area of the traces coupling to the top (e.g.,102,202) and bottom (e.g.,132,432) electrodes. Such a configuration results in less error signal generated by strain and or flexion in the traces. The reduction of the error signal is proportional to the amount of surface area that is removed by the hatched portion408. Embodiments of the hatched portion408may vary the open space amounts according to, among other things, the signal frequencies to be shielded, the width of the traces120, and the like. In general, wider traces120produce more error signal (mechanical crosstalk) and for those embodiments a more aggressive hatching portion408(i.e., larger voids) will further reduce the crosstalk.

As also shown, bottom layer432may include a tab region432for supporting the connective region (e.g., PCB interface204) for the trace pads206. Sensing regions410A-410E are located in areas to align with sensing electrodes318A-318E on an electrode layer316(e.g., as shown inFIG.3). Of course, those of ordinary skill in the art having the benefit of this disclosure would understand that the shapes, sizes, connections, and locations of sensing regions410A-410E are merely exemplary and can vary in accordance with, among other things, the particular application of the sensor system.

As shown inFIGS.3and5, embodiments of the sensor system may include hatched portions208,408where the direction of hatching is a “rectangular” grid that is substantially orthogonal (i.e., intersects in 90° angles) and substantially aligned (i.e., parallel) with the layer edges in each direction. Persons of ordinary skill having the benefit of this disclosure would understand that other alignments are also possible. For example,FIG.6is a schematic of a portion of a layer502in accordance with disclosed embodiments. As shown inFIG.6, hatched portion508is aligned at substantially 45° with respect to layer502edges. One advantage of this hatched portion508is, depending upon orientation and width of the traces (e.g.,120) the amount of coupling may decrease with 45° or 90° hatching. Additionally, manufacturing tolerances may be better with a particular angle for the hatched portion508. Layer502may be a top layer (e.g., like202) or a bottom layer (e.g., like432) and include sensing portions510A-510C as desired. In some embodiments top layer (e.g.,202) and bottom layer (e.g.,432) may have differing hatched portions (e.g.,208,408,508). Other configurations are also possible.

FIG.7is a cross-sectional schematic view of a sensor system600in accordance with disclosed embodiments. As shown, embodiments of sensor system600may include the various top layers (e.g.,2,202,502), bottom layers (e.g.,132,432), electrode layers (e.g.,16,116,316) and a number of dielectric layers (e.g.,108,112,124,128). The actual layers used may depend, among other things, on the application, type of sensing desired, environment for the sensor, and the like. As persons of ordinary skill in the art having the benefit of this disclosure would understand, more, less, different, various thickness, various materials, and the like, layers may be used.

FIG.8is a multi-region angular displacement sensor800in accordance with disclosed embodiments. As shown, embodiments of the sensor system600as disclosed inFIG.7, may be coupled together to form an angular displacement sensor800. For example, by coupling sensor system600A through an elastomeric connector802to a second sensor system600B an angular displacement sensor800(single region, multi-region, or the like) may be implemented. Additional disclosure of the construction, operation, and implementation of such displacement sensor systems800may be found in U.S. Pat. No. 10,551,917, issued to the same assignee, Bend Labs, of Salt Lake City, UT, as the present disclosure, and the disclosure of which is hereby incorporated by reference in its entirety.

As persons of ordinary skill in the art having the benefit of this disclosure would understand, the angular displacement sensor800can be extended to as many regions as desired as indicated by additional elastomeric connectors802and sensor systems600N.

FIG.9is a schematic of a PCB interface204in accordance with disclosed embodiments. In some embodiments, PCB interface is placed on a layer (e.g.,202,502) to provide a connection and mounting point for a PCB (not shown) or other associated electronics. The electrically conductive portions of PCB interface204may be printed with silver nano-particle ink or the like. For example,FIG.9shows trace connector pads206A-206D printed with silver nano-particle ink.

FIG.10is a schematic illustration of a PCB interface204mounted to an elastomeric layer (e.g.,202) in accordance with disclosed embodiments.

Although various embodiments have been shown and described, the present disclosure is not so limited and will be understood to include all such modifications and variations as would be apparent to one skilled in the art.