RESUMO
Digital liquid sample handling is an enabling tool for cutting-edge life-sciences research. We present here an active-matrix thin-film transistor (TFT) based digital microfluidics system, referred to as Field Programmable Droplet Array (FPDA). The system contains 256 × 256 pixels in an active area of 10.65 cm2, which can manipulate thousands of addressable liquid droplets simultaneously. By leveraging a novel TFT device and circuits design solution, we manage to programmatically manipulate droplets at single-pixel level. The minimum achievable droplet volume is around 0.5 nL, which is two orders of magnitude smaller than the smallest droplet ever reported on active-matrix digital microfluidics. The movement of droplets can be either pre-programmed or controlled in real-time. The FPDA system shows great potential of the ubiquitous thin-film electronics technology in digital liquid handling. These efforts will make it possible to create a true programmable lab-on-a-chip device to enable great advances in life science research.
RESUMO
Large-area electronics as switching elements are an ideal option for electrode-array-based digital microfluidics. With support of highly scalable thin-film semiconductor technology, high-resolution digital droplets (diameter around 100 µm) containing single-cell samples can be manipulated freely on a two-dimensional plane with programmable addressing logic. In addition, single-cell generation and manipulation as foundations for single-cell research demand ease of operation, multifunctionality, and accurate tools. In this work, we reported an active-matrix digital microfluidic platform for single-cell generation and manipulation. The active device contained 26,368 electrodes that could be independently addressed to perform parallel and simultaneous droplet generation and achieved single-cell manipulation. We demonstrate a high-resolution digital droplet generation with a droplet volume limit of 500 pL and show the continuous and stable movement of droplet-contained cells for over 1 h. Furthermore, the success rate of single droplet formation was higher than 98%, generating tens of single cells within 10 s. In addition, a pristine single-cell generation rate of 29% was achieved without further selection procedures, and the droplets containing single cells could then be tested for on-chip cell culturing. After 20 h of culturing, about 12.5% of the single cells showed cell proliferation.