By Cameron Chai
Researchers, Dr. Eui-Hyeok Yang and Dr. Chang-Hwan Choi from the Stevens Institute of Technology’s Department of Mechanical Engineering, have received a grant from the National Science Foundation to advance microfluidics research.
This research team is seeking ways to accurately control liquid droplets on the surface of a smart polymer at a voltage below 1 V, paving the way to develop portable digital microfluidic systems.
Such microfluidic systems can be powered directly by AAA batteries and create a lab-on-a-chip, thus allowing users to perform rapid at-home diagnostic tests. The principles of digital microfluidics could be the basis of these novel systems. In digital microfluidics, a voltage is applied to control the liquid droplets on the surface of a smart polymer in order to make the surface either hydrophobic or hydrophilic.
This capability to manipulate the liquid can be used to automate a medical diagnostic test in a handheld device. For instance, a blood sample can be made to follow a path to react with an immobile chemical reagent by applying voltage to the circuit regions. The reaction results are then compared with the anticipated outcome for a negative or positive sample to detect a specific disease or condition, thus opening the door to perform medical testing easily at home.
The voltage supply required for existing digital microfluidics devices to control the liquid droplets is 20-40 V. Such high voltage requirement increases the cost of a biomedical apparatus and makes the device unsuitable for handling and diagnosing most of the biofluids.
The researchers’ work involves the use of tunable wetting on novel surfaces called ‘smart’ polymers, whose affinity towards water can be altered even at an ultra-low voltage, thus enabling the control of the liquid droplets at a voltage below 1 V.
Dr. Yang and Dr. Choi are exploring the prerequisites that impact the capability of a potential apparatus. However, several technical hurdles need to be tackled for the realization of the potential device. If the research proves successful, it will transform digital microfluidics and establish a new horizon for over-the-counter medical tests.