Force-measuring device and related systems

An apparatus, comprising:

• a cover layer comprising an outer surface which can be touched by a digit and an inner surface opposite the outer surface;
• and
• a force-measuring device coupled to the inner surface;
• wherein the force-measuring device comprises:
• a first substrate;
• signal processing circuitry;
• a thin-film piezoelectric stack overlying the first substrate and comprising a piezoelectric layer;
• and
• a plurality of piezoelectric micromechanical force-measuring elements (PMFEs) located at respective lateral positions along the thin-film piezoelectric stack, the signal processing circuitry being coupled to the PMFEs;
• wherein each of the PMFEs comprises:
• (1) a first electrode, (2) a second electrode, and (3) a respective portion of the thin-film piezoelectric stack, the first electrode and the second electrode being positioned on opposite sides of the piezoelectric layer to constitute a piezoelectric capacitor;
• each of the PMFEs is configured to output voltage signals between the respective first electrode and the respective second electrode (PMFE voltage signals) in accordance with a time-varying strain at the respective portion of the piezoelectric layer between the respective first electrode and the respective second electrode resulting from a low-frequency mechanical deformation;
• and
• the signal processing circuitry is configured to read at least some of the PMFE voltage signals.

A system, comprising:

• a force-measuring device;
• and
• a touch-sensing subsystem;
• wherein the force-measuring device comprises:
• a first substrate;
• a thin-film piezoelectric stack overlying the first substrate and comprising a piezoelectric layer;
• and
• a plurality of piezoelectric micromechanical force-measuring elements (PMFEs) located at respective lateral positions along the thin-film piezoelectric stack, a signal processing circuitry being coupled to the PMFEs;
• wherein each of the PMFEs comprises:
• (1) a first electrode, (2) a second electrode, and (3) a respective portion of the thin-film piezoelectric stack, the first electrode and the second electrode being positioned on opposite sides of the piezoelectric layer to constitute a piezoelectric capacitor;
• each of the PMFEs is configured to output voltage signals between the respective first electrode and the respective second electrode (PMFE voltage signals) in accordance with a time-varying strain at the respective portion of the piezoelectric layer between the respective first electrode and the respective second electrode resulting from a low-frequency mechanical deformation;
• and
• the signal processing circuitry is configured to read at least some of the PMFE voltage signals.