Power/Performance Bits: Sept. 9

University of Washington researchers have taken inspiration from a centuries-old clock’s design and created a power harvester that uses natural fluctuations in temperature and pressure as its power source; EPFL scientists have developed a first building-block for photonic “transistors” that requires very low energy to operate marking a big step forward in optical circuit development.

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Harvesting power from air
A centuries-old clock built for a king is the inspiration for a group of University of Washington computer scientists and electrical engineers who hope to harvest power from the air. The clock, powered by changes in temperature and atmospheric pressure, was invented in the early 17th century by a Dutch builder. Three centuries later, Swiss engineer Jean Leon Reutter built on that idea and created the Atmos mechanical clock that can run for years without needing to be wound manually. Now, University of Washington researchers have taken inspiration from the clock’s design and created a power harvester that uses natural fluctuations in temperature and pressure as its power source.

The device harvests energy in any location where these temperature changes naturally occur, powering sensors that can check for water leaks or structural deficiencies in hard-to-reach places and alerting users by sending out a wireless signal.

The power harvester could be placed outside and runs off of temperature changes in the natural world. (Source: University of Washington)

The power harvester could be placed outside and runs off of temperature changes in the natural world.
(Source: University of Washington)

The researchers explained that pressure changes and temperature fluctuations happen all the time in the environment, which could provide another source of energy for certain applications.

Low-energy optical circuit
Optical circuits use light instead of electricity, making them faster and more energy-efficient than electrical systems, and now, EPFL scientists have developed a first building-block for photonic “transistors” that requires record-low energy to operate marking a big step forward in the development and implementation of optical circuits.

Optical (or photonic) circuits work with light rather than electricity, making them 10 to 100 times faster, as well as more energy-efficient due to lower heat loss, better signal-to-noise ratios and therefore less susceptible to interference.

EPFL scientists said they have now fabricated and experimentally tested a silicon-based ‘photonic crystal nanocavity’ (PCN) that requires what they are calling an unprecedentedly low amount of energy to operate as a switch.