Beyond high voltage in the digital microfluidic devices for an integrated portable sensing system

摘要

Digital microfluidics (DMFs) show great potential in the fields of lab-on-a-chip applications for electro-chemical as well as biochemical sensing for decades. Various types of DMF devices have been demonstrated to improve their capabilities such as smaller device size for portability, higher reliability, and multi-purpose applications, etc. Among them, the electrowetting on dielectric (EWOD) is one of the most widely used mechanisms to manipulate droplets due to its good flexibility. On the other hand, the high-voltage application that required for EWOD-type DMF also limits the portability and dimension of the whole system. In this review, we discuss the DMFs which are powered by alternative sources other than electrical sources and evaluate their potential for future portable biochemical assays. Then, the demonstrations reported with the possibility beyond high voltage are discussed starting from lowering voltage requirement for EWODs to the unique methods using mechanical, optical, and energy harvesting to power DMF devices. Finally, the practical applications and prospective on the integrated multi-functional lab-on-a-chip applications are tackled.