Nowadays, electrowetting-on-dielectric (EWOD) chips have become the most popular actuator for droplet-based digital microfluidic biochips. As the complexity of biochemical assay increases, the chip-level design of EWOD chips which integrates electrode addressing and wire routing are widely adopted. Furthermore, to finish many time-sensitive bioassays such as incubation and emerging flash chemistry in a specific time, a high-frequency EWOD is used to satisfy the demand. However, the reliability of the EWOD chip degrades due to the contact angle reduction problem incurred by huge number of switching times of an electrode. Thus, the reliability issue, electrode addressing, and wire routing problem should be considered together in the chip-level design of an EWOD chips. In this paper, a graph-based chip-level design algorithm is presented. By setting the switching-time constraint, the number of switching times can be limited to minimize the impact of contact angle reductions problem. Also, a progressive addressing and routing approach is proposed to overcome the challenge of complex wire routing problem. Experimental results show that the influence of contact angle reduction problem can be effectively minimized by proposed algorithm. A reliable chip-level design with feasible wire routing solution can be generated with number of pins are satisfied.
['Shang-Tsung Yu', 'Sheng-Han Yeh', 'Tsung-Yi Ho']
Reliability-driven chip-level design for high-frequency digital microfluidic biochips