Electronic Device Having Direction-Dependent Strain Elements

A force-sensing layer for sensing a force applied to an electronic device, the force-sensing layer comprising:

• a substrate;
• an array of force-sensitive structures arranged on the substrate, each force-sensitive structure comprising:
• a strain-sensitive element positioned on the substrate and configured to produce a first change in resistance in response to strain along a direction;
• and
• a reference element positioned on the substrate proximate to the strain-sensitive element and configured to produce a second change in resistance in response to strain along the direction that is smaller than the first change in resistance;
• wherein
• the strain-sensitive element and the reference element are disposed in an interlocking spiral pattern.

An electronic device, comprising:

• a component forming an exterior surface of the electronic device;
• a force-sensing layer positioned below the exterior surface and comprising:
• a substrate attached to the component and configured to, in response to a deflection in the exterior surface, produce strain along a series of radial paths extending between a middle region of the substrate and a perimeter of the substrate;
• an array of force-sensitive structures disposed on the substrate, each force-sensitive structure comprising:
• a first strain-sensitive element configured to exhibit a primary sensitivity to strain along a first direction substantially aligned with a respective radial path;
• and
• a second strain-sensitive element positioned adjacent the first strain-sensitive element and configured to exhibit a primary sensitivity to strain along a second direction that is transverse to the first direction;
• wherein
• in response to the deflection in the exterior surface, the first strain-sensitive element exhibits a first change in resistance and the second strain-sensitive element exhibits a second change in resistance that is smaller than the first change in resistance.

An electronic device, comprising:

• a component forming an exterior surface of the electronic device;
• a force-sensing layer positioned below the exterior surface and comprising:
• a substrate attached to the component and configured to strain in response to a deflection in the exterior surface;
• a first force-sensitive structure comprising:
• a first strain-sensitive element disposed on a first surface of the substrate and configured to exhibit a first primary sensitivity to the strain along a first direction;
• and
• a second strain-sensitive element disposed on a second surface of the substrate and aligned vertically with the first strain-sensitive element;
• a second force-sensitive structure comprising:
• a third strain-sensitive element disposed on the first surface of the substrate and configured to exhibit a second primary sensitivity to the strain along a second direction different from the first direction;
• and
• a fourth strain-sensitive element disposed on the second surface of the substrate and aligned vertically with the third strain-sensitive element,
• wherein
• the first direction is based on a first location of the first strain-sensitive element on the first surface of the substrate;
• and
• the second direction is based on a second location of the third strain-sensitive element on the first surface of the substrate.