One of the most popular applications of microfluidics involves developing a ‘lab-on-a-chip’ device to diagnose diseases from a very small biological sample. There already exist some portable devices for diagnosing some conditions. However, the fact that so many moving parts are required to develop more advanced diagnostic devices that might, for example, identify the specific strain of COVID-19 or monitor biomarkers like glucose or cholesterol is a significant hurdle.
Such chips often require materials that are difficult to scale down at the micro-level. Scientists at the University of Minnesota have developed a new microfluidic chip for diagnosing diseases that offer fast results and can be used at home. It uses a minimal number of components and can be powered wirelessly by a smartphone.
Sang-Hyun Oh, an electrical and computer engineering professor and senior author of the study, said, “It’s not an exaggeration that a state-of-the-art, microfluidic lab-on-a-chip system is very labor-intensive. Our thought was, can we get rid of the cover material, wires, and pumps altogether and make it simple?”
Scientists used a technique developed by Oh’s lab to place the tiny electrodes very close together on a 2 cm by 2 cm chip. This generates strong electric fields that pull droplets across the chip and create a similar “leg” of liquid to detect the molecules within.
Scientists placed the electrodes together within proximity of only 10 nanometers. This generates an electric field strong enough that the chip needs less than a volt of electricity to function. This incredibly low voltage requirement allowed scientists to activate the chip using near-field communication signals from a smartphone.
This is the first time scientists have used a smartphone to activate narrow channels without microfluidic structures wirelessly.
Christopher Ertsgaard, a lead author of the study and a recent University alumnus, said, “This is a fascinating, new concept. 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.”
Bruce Batten, founder, and president of GRIP Molecular Technologies, said, “To be commercially successful, in-home diagnostics must be low-cost and easy-to-use. Low voltage fluid movement, such as what Professor Oh’s team has achieved, enables us to meet those requirements. GRIP has had the good fortune to collaborate with the University of Minnesota on developing our technology platform. Linking basic and translational research is crucial to developing a pipeline of innovative, transformational products.”
Journal Reference:
- Sarsgaard, C.T., Yoo, D., Christenson, P.R. et al. open-channel microfluidics via resonant wireless power transfer. Nat Commun 13, 1869 (2022). DOI: 10.1038/s41467-022-29405-2