(Fatih Kocer) A New Transponder Architecture for Long-Range Telemetry Applications & (Pedram Mohseni) Wireless FM Microsystems-on-Chip for Multichannel Biological-Electronic Interfacing

Fatih Kocer and Pedram Mohseni, Graduate Students, University of Michigan
ABSTRACT: (Faith Docer)
Almost a century ago, Nicola Tesla showed that power could be transmitted through air using electromagnetic waves. This phenomenon has been employed in various systems where creating wireless, batteryless devices is essential. The operational range of these devices, however (generally in the order of centimeters), limits their use to very close proximity systems such as cardless entry stations and implanted biomedical sensors and actuators.

In this presentation, I will present a new architecture for very long-range, remotely powered, sensor telemetry applications. Two prototypes employing this architecture will be demonstrated. The first one is an RFID device-transmitting user programmable 8-bit data on a binary phase shift keyed (BPSK) 900 MHz carrier. The second one is a wireless and batteryless temperature sensor, transmitting the ambient temperature change as a frequency shift of the 2.4 GHz carrier. Carrier frequencies on both devices are generated on-chip by a low power, low phase noise LC oscillator. The devices are fully integrated and are fabricated in a 5-metal CMOS process. Wireless operation range of more than 18 meters is verified in anechoic chamber tests. This is the longest telemetry range reported to date.

ABSTRACT: (Pedram Mohseni)
Wireless single/multi-channel telemetric systems have always been of great interest to researchers in the biology and neurophysiology communities due to their advantage of simultaneous recording and transmission of one or more physiological parameters. Although the emergence of high-quality surface mount electrical components in the past has remarkably facilitated the implementation of such systems, the majority of the current recording devices still have either prohibitively large dimensions and weight, or high power consumption that makes them impractical for general-purpose low-power applications. Combining application-specific integrated circuit (ASIC) design techniques with micromachined biopotential recording electrode technology can significantly reduce the overall dimensions, weight, and power consumption of such systems, offering low-power multichannel radio-telemetry recording devices that can be used in closed-loop neural prosthesis to study either the peripheral or central nervous system at the cellular level. In this seminar, I will talk about the design, implementation, testing, and performance characterization of wireless FM recording microsystems-on-chip to remotely monitor input biopotentials recorded by micromachined microelectrode arrays. The functionality of the fabricated devices in an experimental procedure will be demonstrated via single channel wireless in vivo recording of spontaneous neural activities in the auditory cortex of awake primates at different transmission ranges up to 0.5m. These devices serve as valuable test vehicles to obtain a fundamental knowledge of numerous limitations and trade-offs involved in the design of wireless integrated recording biomicrosystems.