Extended Data Fig. 3: Current control module performance and monitoring results.
From: Encoding of tactile information in hand via skin-integrated wireless haptic interface
a, Diagram showing how the hand is in series in the closed circuit and the position of CCM in this circuit. A virtual ground (VGND) whose potential changes according to permitted current is connected to the common cathode electrode (CE). SE, stimulating electrode. GND, ground. b, Detail schematic of the CCM and current monitoring circuit. Current control part is circled with red dashed lines, mainly composed of a current mirror where the controlled current of the 2nd transistor (ICTL)is identical to the reference current through the 1st transistor (IREF). Monitoring part is circled with blue dashed lines, mainly composed of a fixed resistor (typically 50 Ohm) and an operational amplifier functions as a voltage follower, where the current passing through the resistor is transformed into voltage signal and the duplicated signal being sensed by a 14 bit analogue-digital converter (ADC) on the MCU. c, Measured current under different wireless commands using commercial data acquisition system (Keithley DAQ 6510) d, Zoomed-in details of the current waveform when switching intensities. e, Voltage value between two sides of the resistor, sensed by the ADC of MCU. f, Zoomed in details of the voltage waveform. Time scales of e is identical with c while f is identical with d.
