“To be ‘complete,’ a computer system must have an input of data, the ability to process that data – meaning process and store it, make decisions about what to do next – and, ultimately, the ability to output the data,” says David Blaauw, a professor of electrical engineering and computer science at the University of Michigan. “The sensors are the input and the radios are the output. The other key to being a complete computer is the ability to supply its own power.”Think of these as smart sensors. With a power source, sensor and radio link, these could be used in places where it's too difficult to get something bigger. Early talk is using these for medical purposes: monitoring processes inside the body, as well as conducting EKGs and detecting and monitoring tumor growth. If you're of a certain age, you'll recall the 1966 film Fantastic Voyage. It's not a miniature submarine with an equally miniature Raquel Welch in it, but the Micro Mote can actually be injected into the body to perform some of these functions.
rim of a nickel. You'll note the glaring absence of a keyboard, mouse or monitor. Instructions are sent to the Micro Mote by flashing a light at it (On Off Keying). The output comes over the radio link, which they say is short range, on the order of 2 meters.
The biggest problem in creating these dedicated computers is power. The Micro Mote includes a "solar cell" which produces enough power to run the computer even indoors. With a 1mm2 solar cell producing 20nW (20 nanoWatts, or 20 billionths of a Watt), the device can harvest enough energy under ambient light to run perpetually. The device’s standby current consumption is 2nA - 2 billionths of an Amp - claimed to be about one millionth of the standby current in typical cellphone.
The University of Michigan website has some ideas on interesting uses for "smart dust". I think we can count on some of these being developed!