Devices that make use of this ultralow power transistor could function for months, maybe years, without batteries, according to the team.
The transistor “scavenges” energy from its environment in a manner similar to a computer in “sleep” mode. It can harness the tiny leak of electrical current, also called a near-off-state current. Researchers suggest that such a transistor could be used in wearable or implantable devices connected to the Internet of Things.
The transistor’s operating voltage is less than a volt and its power consumption is below a billionth of a watt, according to researchers..
“We’re challenging conventional perception of how a transistor should be,” co-author Arokia Nathan said in prepared remarks. “We’ve found that these Schottky barriers, which most engineers try to avoid, actually have the ideal characteristics for the type of ultralow power applications we’re looking at, such as wearable or implantable electronics for health monitoring.”
Produced at low temperatures and printed onto almost any material, the transistors utilize a “Schottky barrier” – the point of contact between the metal and semiconducting components of a transistor.
“If we were to draw energy from a typical AA battery based on this design, it would last for a billion years,” first author Sungsik Lee added. “Using the Schottky barrier allows us to keep the electrodes from interfering with each other in order to amplify the amplitude of the signal even at the state where the transistor is almost switched off.”
“This will bring about a new design model for ultralow power sensor interfaces and analogue signal processing in wearable and implantable devices, all of which are critical for the Internet of Things,” Nathan said.