A battery-free multi-channel digital neural/EMG telemetry system for flying insects

Most recently reported multi-channel wireless neural telemetry systems are not suitable for studying insects in flight because of mass and battery limitations. We present preliminary results toward the development of a digital neural/EMG telemetry system with a measured flight package mass of only 38 mg. This system includes a single-chip telemetry system employing RF power harvesting for battery-free operation, with communication via modulated backscatter in the UHF (902-928 MHz) band. An on-chip 11-bit ADC digitizes 10 neural channels with a sampling rate of 26.1 kSps and 4 EMG channels at 1.63 kSps. We also present a companion base station transceiver including an RF transmitter of +36 dBm (4 W) output power to wirelessly power the IC, and a digital receiver with a threshold sensitivity of -70 dBm for 10^-5 BER at 5.0 Mbps to receive the data stream. The chip was fabricated in a commercial 0.35 μm 4M1P (4 metal, 1 poly) CMOS process. The die measures 2.36 × 1.88 mm, and is 250 μm thick. Measurements to date indicate that the chip is fully functional as designed.