A touch sensing system including an ultrasonic transmitter and a force-sensing device, the force-sensing device comprising: a substrate; an array of sensor pixel circuits disposed on the substrate; discrete elements of a piezoelectric film layer, each discrete element corresponding with an individual sensor pixel circuit; a plurality of pixel input electrodes, each pixel input electrode configured for making an electrical connection between a first side of a discrete element of the piezoelectric layer and one of the sensor pixel circuits; a receiver bias electrode configured for making an electrical connection with a second side of discrete elements of the piezoelectric layer; and a control system configured to: receive a signal from one or more of the sensor pixel circuits, the signal corresponding to a force applied to one or more discrete elements of the piezoelectric film layer; and determine a location of an object exerting the force when the control system is configured to operate the touch sensing system in a force-sensing mode, wherein the control system is further configured to operate the touch sensing system in an ultrasonic imaging mode or the force-sensing mode; and maintain the ultrasonic transmitter in an "off" state when operating the touch sensing system in the force-sensing mode, wherein in the ultrasonic imaging mode, the ultrasonic transmitter is in an "on" state, and the force-sensing device is configured to function as an ultrasonic receiver. a substrate; an array of sensor pixel circuits disposed on the substrate; discrete elements of a piezoelectric film layer, each discrete element corresponding with an individual sensor pixel circuit; a plurality of pixel input electrodes, each pixel input electrode configured for making an electrical connection between a first side of a discrete element of the piezoelectric layer and one of the sensor pixel circuits; a receiver bias electrode configured for making an electrical connection with a second side of discrete elements of the piezoelectric layer; and a control system configured to: receive a signal from one or more of the sensor pixel circuits, the signal corresponding to a force applied to one or more discrete elements of the piezoelectric film layer; and determine a location of an object exerting the force when the control system is configured to operate the touch sensing system in a force-sensing mode, wherein the control system is further configured to operate the touch sensing system in an ultrasonic imaging mode or the force-sensing mode; and maintain the ultrasonic transmitter in an "off" state when operating the touch sensing system in the force-sensing mode, wherein in the ultrasonic imaging mode, the ultrasonic transmitter is in an "on" state, and the force-sensing device is configured to function as an ultrasonic receiver. receive a signal from one or more of the sensor pixel circuits, the signal corresponding to a force applied to one or more discrete elements of the piezoelectric film layer; and determine a location of an object exerting the force when the control system is configured to operate the touch sensing system in a force-sensing mode, wherein the control system is further configured to operate the touch sensing system in an ultrasonic imaging mode or the force-sensing mode; and maintain the ultrasonic transmitter in an "off" state when operating the touch sensing system in the force-sensing mode, wherein in the ultrasonic imaging mode, the ultrasonic transmitter is in an "on" state, and the force-sensing device is configured to function as an ultrasonic receiver.