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.

数十年来，数字微流控（DMF）在芯片实验室中的电化学和生物化学传感领域显示出巨大的潜力。已经证明了各种类型的DMF设备可以提高其功能，例如，更小的设备尺寸，便于携带，更高的可靠性以及多用途应用等。其中，电介质电润湿（EWOD）是最广泛使用的机制之一，由于其良好的柔韧性，可操作液滴。另一方面，EWOD型DMF所需的高压应用也限制了整个系统的便携性和尺寸。在本文中，我们将讨论由电源以外的其他来源提供动力的DMF，并评估其在未来便携式生化分析中的潜力。然后，从降低EWOD的电压要求到使用机械，光学和能量收集为DMF设备供电的独特方法，讨论了报道的超出高电压可能性的演示。最后，解决了实际应用和集成多功能片上实验室应用的前景。