FROM SMARTPHONES TO DIAGNOSTICS: LOW COST ELECTRONICS FOR PROGRAMMABLE DIGITAL MICROFLUIDICS AND SENSING Hywel Morgan, Sumit Kalsi, Martha Valiadi, Ioannis Zeimpekis, Chunxiao Hu, Sun Kai and Peter Ashburn Faculty of Physical Sciences and Engineering, and Institute for Life Sciences University of Southampton, ABSTRACT We are developing all-electronic sensing and diagnostic platforms based on low-cost electronics as found in smartphones. Our concept is a system that combines digital microfluidics (DMF), based on Electro Wetting on Dielectric (EWOD) with direct electrical readout of assay chemistry using simple transistors. A programmable DMF technology has thousands of electrodes, each of which contains sen- sors to measure droplet characteristics. These devices are made using Thin Film Transistor (TFT) tech- nology. The same approach is used to make Si nanoribbon sensors that enable direct electrical readout of assays. The system enables many complex assays to be pre-programmed and performed in parallel. KEYWORDS: EWOD, Digital Microfluidics, Impedance Sensing, Nano-wire, INTRODUCTION Digital microfluidic (DMF) micro-devices offer the prospect of low-cost fully automated assays. DMF exploits Electro Wetting-On-Dielectric (EWOD) to manipulate single droplets using arrays of microelectrodes. Traditional “passive” EWOD devices use hard-wired electrodes and limited in their utility and cannot be re-configured owing to the limited number of independently electrodes that can be operated on a single device. To address this problem, in collaboration with Sharp [2,3], the authors have developed EWOD devices controlled by Thin Film Transistor (TFT) electronics, so-called Active Matrix AM-EWOD. These devices have large arrays of individually programmable electrodes facilitating the simultaneous and independent manipulation of many droplets in parallel. They provide a very high level of flexibility in defining droplet size and shape and are manufactured using low-temperature thin film processes developed for the consumer electronics industry, for example mobile phone displays. Each pixel (or electrode) in the device incorporates a sensor to monitor the volume and position of droplets, providing a unique all-electronic control of an assay. AM-EWOD devices are therefore ideally suited for point-of-care molecular testing as they provide a highly flexible and customisable platform capable of performing complex fluid manipulation of nanolitre volumes. To complement this programmable liquid handling platform, we are also developing electronic sensing and assay readout technologies based on nano-ribbon transistor sensors. These transistors can also in principle be manufactured using the thin film large area processes used in the display industry, making them particularly appealing as very low cost electronic readout systems. Combining these transistors with DMF systems should provide an integrated programmable all electronic assay platform sharing a common low-cost manufacturing approach. METHODS Digital Microfluidics The TFT Digital Microfluidic device is shown in Figure 1 [1,2]. It has 16,800 individual elements or electrodes which can be used to move droplets by EWOD. Each of these elements also contains a sensor which can detects droplets and measure its size or volume. This enables real time feedback of droplet size and position. Many different assays have been implemented on the device. We are currently using the 254 978-0-9798064-8-3/μTAS 2015/$20©15CBMS-0001 19 th International Conference on Miniaturized Systems for Chemistry and Life Sciences October 25-29, 2015, Gyeongju, KOREA