Wireless integrated microsystems rely heavily on the availability of low-power microelectronics for control, data processing, and communication. Power-efficient circuit design enables small form factors/low cost, as well as long battery life (or opens up the possibility of energy scavenging). The Micropower Circuits Thrust aims at greatly reducing the power budgets of integrated circuits using a range of techniques that are suitable for incorporation into generic microsystems. Both digital and analog circuits are targeted, with primary emphasis on the digital processing domain. Furthermore, the Thrust includes low-power compilation work, as well as the software development for the WIMS testbeds. Highlights are given below:

Next-generation WIMS microcontroller design work is ongoing with a focus on application to controlling a neural prosthesis. Novel aspects of this design include architectural optimizations to reduce power, as well as software-driven dynamic frequency and voltage scaling, along with body biasing for process variation compensation. Embedded software development for this project also continues, with joint work across many institutions on porting code to the Cochlear Testbed. Finally, interface circuits have been designed for use in testing of the Environmental Monitoring Testbed.

At the same time, thrust members are continuing fundamental research to support the WIMS mission of a generic microsystem platform. Specifically, researchers in the Thrust are pursuing energy-scavenging techniques, microbatteries, and hybrid power sources. Building upon a previous WIMS effort to optimize a microcontroller for the ultimate in low-standby mode power (the Phoenix Processor), we have developed a 3-D stacked system of a microbattery, microcontroller, and solar cells that is 8.75mm3 in volume and can run nearly perpetually at typical sensor node duty cycles. Many of the projects in microbatteries, sensors, and microcontrollers are coming together in an intraocular pressure sensor platform for glaucoma research.