Batteryless sensors on verge of release
A wireless ultra-low-power microchip set for release next year by American firm PsiKick could be a key driver in the development of the Internet of Things. The company was launched by two university professors who have spent the last decade developing ‘sub-threshold’ microchips. Their creation uses the small amount of current that flows through a circuit’s transistor, even when it is switched off, to operate with 100 to 1,000 times less power consumption than comparable microchips.
By using power so effectively the wireless microchips will not even need batteries, it is expected. They could draw energy from the environment through the harvesting of ambient radio wave energy or through peoples’ footsteps where piezoelectric flooring has been installed, for instance.
Sub-threshold processing works by using a supply voltage that is less than a single transistor’s threshold voltage – that is the voltage necessary to turn the switch on or off. Switches in a circuit with a supply voltage below the threshold are considered to be switched off but the current does not fall to zero straight away. This leakage of energy is harvested to perform operations and by lowering the voltage of the unit the overall power consumption of the unit is lowered dramatically.
Several other companies are working on similar projects meaning a reality where a wide range of sensors are truly camouflaged in the environment – needing no power or maintenance – now cannot be far away.