Patent ID: 11898924
Assignee: THE UNIVERSITY OF BRITISH COLUMBIA
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 10:
11. A sensor unit for detecting shear force applied to the sensor in a tangential direction that is generally tangential to an active surface of the sensor at a location where the shear force is applied, the sensor unit comprising:
a first deformable sheet comprising the active surface on one side of the first deformable sheet and a first inner surface on an opposing side of the first deformable sheet;
a second deformable sheet comprising a second inner surface on one side of the second deformable sheet and an outer surface on an opposing side of the second deformable sheet;
wherein the first inner surface has a first inner surface normal vector oriented toward the second inner surface and is spaced apart from the second inner surface in a direction along the first inner surface normal vector;
wherein one of the first and second deformable sheets supports one or more electrically conductive sensor electrodes and the other one of the first and second deformable sheets supports an electrically conductive base electrode;
a deformable dielectric layer located in at least some of a volume between the first inner surface and the second inner surface;
one or more support dielectric pillars located within the deformable dielectric layer, each support dielectric pillar bonded to one of the first inner surface and the second inner surface at a bonded end of the support dielectric pillar and having a non-bonded end that is capable of translation relative to the other one of the first inner surface and the second inner surface;
wherein the one or more support dielectric pillars are spaced apart from each of the plurality of bonded dielectric pillars in one or more directions tangential to the first inner surface to thereby maintain a space between the first and second deformable sheets;
wherein, in response to shear force oriented in a direction tangential to the active surface, the first sheet deforms and, as a result of this deformation, at least one of the one or more sensor electrodes moves in the tangential direction relative to the base electrode; and
wherein, for such movement of the at least one of the one or more sensor electrodes, a first capacitance between the at least one of the one or more sensor electrodes and the base electrode either: increases relative to a capacitance between the at least one of the one or more sensor electrodes and the base electrode in an absence of the shear force; or decreases relative to the capacitance between the at least one of the one or more sensor electrodes and the base electrode in the absence of the shear force.