In Brief
  • Engineers from the University of Cambridge have created an ultra low power transistor that can run for a long time without a power source.
  • This tech could be used in various sensor interfaces and wearable devices, or in more autonomous electronics that can harness energy from their environments.

Scavenging Power

As electronic devices become more compact and powerful, conventional methods for manufacturing electrical components simply won’t do. The problem lies in the fact that current systems require a huge battery and their components are too bulky.

However, that all could change, as engineers from the University of Cambridge have created an ultra low power transistor that can run for a long time without a power source.

Basically, transistors are semiconductor devices that function like a faucet. Turn a transistor on and the electricity flows,  turn it off and the flow stops. When a transistor is off however, some electric current could still flow through, just like a leaky faucet. This current, which is called a near-off-state, was exploited by the engineers to power the new transistors.

 

Credit: University of Cambridge
Credit: University of Cambridge

These new transistors are able to scavenge power from its surrounding environment allowing a battery to last longer. Dr Sungsik Lee, the paper’s first author, also from the Department of Engineering says, “if we were to draw energy from a typical AA battery based on this design, it would last for a billion years.” The new design could be produced in low temperatures and they are versatile enough to be printed on materials like glass, paper, and plastic.

Smaller Devices

The transistor’s design also utilizes a ‘non-desirable’ characteristic, namely the ‘Schottky barrier’ to create smaller transistors. Transistors today cannot be manufactured into smaller sizes since the smaller a transistor gets, the more its electrodes influence each other, causing a non-functioning transistor. The use of the Schottky barrier in the new design creates seal between the electrodes that make them work independently from each other.

According to Arokia Nathan of Cambridge’s Department of Engineering, the second author of the paper, this new design can see use in various sensor interfaces and wearable devices that require only a low amount of power to run. Professor Gehan Amaratunga, Head of the Electronics, Power and Energy Conversion Group at Cambridge’s Engineering Department sees its use in more autonomous electronics that can harness energy from their environments similar to a bacteria.