A Low-Power, Single-Chip Electronic Skin Interface for Prosthetic Applications

A low-power, single-chip electronic skin interface is presented. Its small size and reduced battery requirements are ideal for advanced prosthetic limbs that utilize electronic skin to provide their user tactile feedback. The architecture consists of multiple charge-sensitive analog front ends (AFEs) interfaced to a central, 16-bit microcontroller core which is capable of processing the sensory information in real-time. Event driven operation allows the chip to monitor all input channels while idle and consuming minimal energy. A test chip has been fabricated in a 0.13 mu m CMOS technology and implements 13 AFE channels. Its functionality is demonstrated by interfacing the chip to a prototype electronic skin based on polyvinylidene fluoride (PVDF) piezoelectric sensors. Signals from the sensors are captured by the presented chip and processed to calculate the corresponding charge. This is accomplished by programming the microcontroller with a custom software algorithm implemented in C, granting the system the flexibility to interface to different types of sensors. The single-chip electronic skin system consumes 7.0 mu W per channel and 76.5 mu W in the example application, making it suitable for use with battery-powered prosthetics.