Nanoscale Sensors Transmit Data From Living Tissue
Sensors based on an integrated circuit, solar cells and GaAs-based LEDs fit 30,000 to a penny
Cornell University researchers who build nanoscale electronics have developed microsensors so tiny, they can fit 30,000 on one side of a penny. They are equipped with an integrated circuit, solar cells and GaAs-based LEDs that enable them to harness light for power and communication. And because they are mass fabricated, with up to 1 million sitting on an 8-inch wafer, each device costs a fraction of that same penny.The team's paper was published in PNAS.
The sensors can be used to measure inputs like voltage and temperature in hard-to-reach environments, such as inside living tissue and microfluidic systems. For example, when rigged with a neural sensor, they would be able to noninvasively record nerve signals in the body and transmit findings by blinking a coded signal via the LED. As a proof of concept, the team successfully embedded a sensor in brain tissue and wirelessly relayed the results.
The collaboration is led by Paul McEuen, professor of physical science, and Alyosha Molnar, associate professor of electrical and computer engineering. Working with the paper's lead author, Alejandro Cortese, a Cornell Presidential Postdoctoral Fellow, they devised a platform for parallel production of their optical wireless integrated circuits (OWICs) - microsensors the size of 100 microns (a micron is one-millionth of a meter), mere specks to the human eye.
The researchers describe the OWICS as like nano-scale smartphones that can be specialised with apps. But rather than rely on cumbersome radio frequency technology, as cellphones do, the researchers looked to light as a potential power source and communication medium.
McEuen, Molnar and Cortese have launched their own company, OWiC Technologies, to commercialise the microsensors. A patent application has been filed through the US Center for Technology Licensing. The first application is the creation of e-tags that can be attached to products to help identify them.
The tiny, low-cost OWICs could potentially spawn generations of microsensors that use less power while tracking more complicated phenomena.
'Microscopic Sensors Using Optical Wireless Integrated Circuits' by Alejandro J. Cortese et el; PNAS April 17, 2020.