“…The power and data are transmitted to a piezoelectric receiver (RX) connected to either a sensor (for collecting data) or an actuator (for stimulating its environment). The data can flow from the transmitter to the receiver (downlink communication for sending excitation commands) [2,15,16,18,20,43], from the receiver to the transmitter (uplink communication to transmit sensor data and device status) [1,4,6,8,10,11,14,41,42,[44][45][46], or in both directions either simultaneously (full-duplex) [40,47] or in turns (half-duplex/time multiplexing) [21,36,[48][49][50][51]. Downlink communication can be as simple as switching between turning the transmitter on and off, i.e.…”