Researchers at the University of Michigan have developed two sensing devices.
The first is a tiny pressure monitor that can be implanted into the eye of the patients suffering from glaucoma. The second is a minute radio that needs no fine tuning and can be connected to a network that could detect pollution, control building strength and security systems.
Dennis Sylvester and David Blaauw have designed the pressure sensor that constantly monitors the progress of glaucoma. It measures 1 cubic millimeter and fits a low-power microprocessor with memory, a thin-film battery, a solar cell and a wireless radio. The radio antenna relays information to an external control monitor near the eye. The processor deploys power gating and a power efficient sleep mode. It records data every 15 minutes, consumes 5.3 nanowatts of power, while the battery needs to be exposed to sunlight for an hour and a half for recharging. It stores three weeks of information.
Wentzloff and Kuo-Ken Huang have designed a radio with an on-chip antenna. The crystal reference chooses a radio frequency band. Removing this crystal reduces the radio size. It will also track time. The CMOS technology helps control the way it oscillates to electrical signals.