Pressure Sensing Apparatuses and Methods

• US 20120062245A1
• Filed: 09/09/2011
• Published: 03/15/2012
• Est. Priority Date: 09/10/2010
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Bao, Zhenan, Mannsfeld, Stefan Christian Bernhardt, Locklin, Jason, Tee, Benjamin Chee-Keong
• Granted Patent: US 9,281,415 B2
• Time in Patent Office: Days
• US Class Current: 324/661
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence
• CPC Class Codes: G01L 1/148 using semiconductive material, e.g. silicon
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: H01L 29/84 controllable by variation of applied mechanical force, e.g. of pressure
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 85/623 containing five rings, e.g. pentacene
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

Sensors, sensing arrangements and devices, and related methods are provided. In accordance with an example embodiment, an impedance-based sensor includes a flexible dielectric material and generates an output based on pressure applied to the dielectric material and a resulting compression thereof. In certain embodiments, the dielectric material includes a plurality of regions separated by gaps and configured to elastically deform and recover in response to applied pressure.

Claims

1. An apparatus comprising:

a dielectric structure including a plurality of elastomeric regions separated from one another by space regions, the elastomeric regions being configured and arranged, in response to pressure, to compress and thereby exhibit a changed effective dielectric constant corresponding to a state of compression of the elastomeric regions; and

a sense circuit including a plurality of impedance-based sensors, each impedance-based sensor including a portion of the dielectric structure and configured and arranged to respond to the change in dielectric constant by providing an indication of the pressure applied to the dielectric structure adjacent each sensor.

2. The apparatus of claim 1, wherein the respective elastomeric regions are configured and arranged to exhibit a different effective dielectric constant, relative to other ones of the elastomeric regions, in response to different pressures being applied to the respective elastomeric regions.

3. The apparatus of claim 2, wherein the sense circuit is configured and arranged to respond to a change in dielectric constant at different ones of the elastomeric regions by providing an indication of both the pressure applied to the elastomeric region and the position of the elastomeric region at which the pressure is applied.

4. The apparatus of claim 2, wherein each sensor provides an output indicative of a state of compression of the elastomeric material adjacent the sensor, and the sense circuit is configured and arranged to provide an indication of the position of the respective sensor providing each output.

5. The apparatus of claim 2, wherein the elastomeric regions are configured and arranged to, relative to one another and a distance between the elastomeric regions, reversibly store and release energy via elastic deformation of the respective elastomeric regions.

6. The apparatus of claim 2, wherein the elastomeric regions are configured and arranged relative to one another and the spacing therebetween to deform elastically in response to the application of external pressure that, absent the space regions between the elastomeric regions, would effect visco-elastic creep in the elastomeric material.

7. The apparatus of claim 2, wherein the space regions include a material having a compression property that is different than a compression property of the elastomeric material.

8. The apparatus of claim 1, wherein at least one of the sensors includes a portion of the dielectric structure configured and arranged to exhibit a response to applied pressure that is different than a response to applied pressure exhibited by a portion of the dielectric structure of a different one of the sensors, the respective sensors being configured and arranged to provide outputs that are different than one another in response to a common pressure applied to the dielectric structures of the sensors.

9. The apparatus of claim 1, wherein the sense circuit includes a group of coplanar sensors oriented in different directions and configured to exhibit a common response to a vertical pressure applied in a direction that is about perpendicular to the plane in which the sensors lie, and to exhibit different responses, relative to at least one of the other sensors in the group, to stress exerted onto the sensors in the direction of the plane in which the sensors lie.

10. The apparatus of claim 1, further including a logic circuit configured and arranged to process outputs from the sensors to determine at least one of a pressure applied to at least one of the sensors and a location of the pressure relative to the sensors.

11. A pressure sensor comprising:

a flexible dielectric layer including a plurality of dielectric material regions separated from one another by a gap region, the flexible dielectric layer being configured and arranged to exhibit dielectric characteristics that vary in response to a pressure applied to the flexible dielectric layer; and

first and second electrodes separated by the flexible dielectric layer, the electrodes being configured and arranged to provide an electrical output indicative of the dielectric characteristic of the flexible dielectric layer, therein providing an indication of pressure applied to the flexible dielectric layer.

12. The sensor of claim 11, wherein the dielectric material regions are configured and arranged to, relative to one another and the gaps between the dielectric material regions, reversibly store and release energy via elastic deformation of the respective dielectric material regions.

13. The sensor of claim 11, wherein the first and second electrodes are configured and arranged to provide an electrical output including at least one of

a capacitive output indicative of a capacitance between the electrodes, via the dielectric layer, the electrodes being in a stacked arrangement with the dielectric layer being compressed between the electrodes, and

a current output at a first one of the electrodes, the current output being responsive to a bias applied to a channel region by a second one of the electrodes, via the dielectric layer.

14. A circuit comprising:

an organic semiconductor substrate;

a plurality of pressure sensors at different locations on the substrate, each sensor including

source and drain electrodes coupled by a channel region that is in the substrate and adjacent the gate dielectric,

a gate configured and arranged to apply a bias to the channel region,

an elastic dielectric layer between the gate and the channel region, the dielectric layer including a plurality of patterned dielectric regions separated from one another by a space, the dielectric regions being configured and arranged to elastically deform in response to pressure and to exhibit a dielectric characteristic that changes in response to the elastic deformation of the dielectric region; and

interconnecting conductors configured and arranged to couple a signal from each of the sensors for detecting an electrical response of the sensors to pressure applied to the dielectric regions.

15. The circuit of claim 14, wherein each of the dielectric regions is configured and arranged to deform separately, relative to the other dielectric regions, in response to different pressures applied to the respective dielectric regions.

16. The circuit of claim 14, wherein the dielectric regions exhibit different dielectric properties based upon a pressure applied to the regions and are configured and arranged to, relative to one another and a distance between the dielectric regions, reversibly store and release energy via elastic deformation of the respective dielectric regions.

17. The circuit of claim 16, wherein the dielectric regions are configured and arranged, relative to one another and the spacing between the dielectric regions, to deform elastically in response to the application of external pressure that, absent the space between the dielectric regions, would effect visco-elastic creep in at least one of the dielectric regions.

18. The circuit of claim 14, further including a flexible substrate, the dielectric layer being connected to the flexible substrate and configured and arranged to compress in response to pressure applied to the flexible substrate.

19. A device comprising:

a sensor substrate configured and arranged for insertion into a cavity;

a dielectric material on the sensor substrate and having a plurality of dielectric material regions separated by a space, the dielectric material being configured and arranged, with the substrate, to exhibit different dielectric characteristics based upon pressure applied to the dielectric material via a material within the cavity;

first and second electrodes on the dielectric material and configured and arranged to generate an output based on the dielectric characteristic of the dielectric material; and

a circuit connected to the electrode and configured and arranged to provide an output from the first and second electrodes for access outside of the cavity, while the sensor substrate is inserted within the cavity.

20. A method of manufacturing sensor device, the method comprising:

forming a plurality of sensors respectively including an impedance-based device having a dielectric material and an electrode, each sensor configured and arranged to generate an output at the electrode based on pressure applied to the dielectric material; and

coupling the sensors with interconnecting circuits configured and arranged to provide an output indicative of, for each sensor, both the pressure applied to the dielectric material and the location of the applied pressure.