User-input systems and methods of detecting a user input at a cover member of a user-input system

A user-input system, comprising:

• a force-measuring device comprising a semiconductor die, the semiconductor die comprising a micro-electro-mechanical systems (MEMS) portion, the MEMS portion comprising a first piezoelectric micromechanical force-measuring element (PMFE);
• a plurality of PMFEs including the first PMFE;
• an electrically non-conducting cover member;
• an elastic circuit board substrate interposed between the PMFEs and the cover member and mechanically coupled to the cover member and to the PMFEs, the force-measuring device being mounted to and electrically connected to the elastic circuit board substrate;
• sensor electrodes positioned on or in the elastic circuit board substrate;
• and
• a signal processor electronically coupled to the PMFEs and the sensor electrodes;
• wherein:
• the cover member undergoes a primary mechanical deformation in response to forces imparted at the cover member;
• the elastic circuit board substrate transmits a portion of the primary mechanical deformation to the PMFEs resulting in a concurrent secondary mechanical deformation of the PMFEs;
• each of the PMFEs is configured to output voltage signals in accordance with a time-varying strain at the respective PMFE resulting from the secondary mechanical deformation;
• the signal processor is configured to determine force data in accordance with the voltage signals output from each of the PMFEs;
• the signal processor is configured to measure capacitance data for each of the sensor electrodes;
• and
• the signal processor is configured to detect a user input in accordance with the force data and the capacitance data.