Using a technique pioneered by Oh’s lab, the researchers placed tiny electrodes very close together on a 2 cm by 2 cm chip, which generate strong electric fields that pull droplets across the chip and create a similar “leg” of liquid to detect the molecules within.
Because the electrodes are placed so closely together, with only 10 nanometers of space between, the resulting electric field is so strong that the chip needs less than a volt of electricity to function. This incredibly low voltage requirement allowed the researchers to activate the chip using near-field communication signals from a smartphone, the same technology used for contactless payment in stores.
This is the first time researchers have been able to use a smartphone to wirelessly activate narrow channels without microfluidic structures, paving the way for cheaper, more accessible at-home diagnostic devices.
“This is a very exciting, new concept,” said Christopher Ertsgaard, lead author of the study and a recent University alumnus. “During this pandemic, I think everyone has realized the importance of at-home, rapid, point-of-care diagnostics. And there are technologies available, but we need faster and more sensitive techniques. With scaling and high-density manufacturing, we can bring these sophisticated technologies to at-home diagnostics at a more affordable cost.”
Oh’s lab is working with Minnesota startup company GRIP Molecular Technologies, which manufactures at-home diagnostic devices, to commercialize the microchip platform. The chip is designed to have broad applications for detecting viruses, pathogens, bacteria and other biomarkers in liquid samples.
“To be commercially successful, in-home diagnostics must be low-cost and easy-to-use,” said Bruce Batten, founder and president of GRIP Molecular Technologies. “Low voltage fluid movement, such as what Professor Oh’s team has achieved, enables us to meet both of those requirements. GRIP has had the good fortune to collaborate with the University of Minnesota on the development of our technology platform. Linking basic and translational research is crucial to developing a pipeline of innovative, transformational products.”
The research is published in Nature Communications.
Source: University of Minnesota
Source: Healthcare in Europe