The University of Michigan Department of Electrical Engineering and Computer Science has created a prototype for what is believed to be the first complete millimeter-scale computing system. The prototype is an implantable eye pressure monitor for glaucoma patients. The whole system measures just over 1 cubic millimeter, and has an ultra low-power microprocessor, a pressure sensor, memory, a thin-film battery, a solar cell, and a wireless radio with an antenna that can transfer data to an external device held near the eye.
The work is being led by professors Dennis Sylvester and David Blaauw, and assistant professor David Wentzloff. According to Sylvester, "This is the first true millimeter-scale complete computing system. Our work is unique in the sense that we're thinking about complete systems in which all the components are low-power and fit on the chip. We can collect data, store it and transmit it. The applications for systems of this size are endless."
The processor in is the third generation of the researchers' Phoenix chip, which uses a unique power gating architecture and an extreme sleep mode to keep the power consumption at a minimum. The system wakes to take measurements every 15 minutes, and consumes an average of 5.3 nanowatts. The battery charges using the solar cell, and requires 10 hours of indoor light or 1.5 hours of sunlight each day. It is able to store up to a week's worth of information. The device is expected to be available several years from now.
The next step is to allow the device to communicate with others like it. Professor Wentzloff is working with doctoral student Kuo-Ken Huang to develop a consolidated radio with an on-chip antenna. This eliminates the need for external crystals that are relied on today for two isolated devices to talk to each other.
So maybe there could be several of these tiny computers in one persons body, all communicating with each other...are we getting closer to this? Hopefully not so visible, though.