We demonstrate a new technique of heating aqueous droplets on conventional EWOD electrodes by using high-frequency high-voltage AC signals. At high actuation frequencies (10–1000 kHz), the droplet temperature rises due to Joule heating from the ohmic currents inside the drop. Using this direct heating technique, we were able to achieve temperatures of 93–94 °C, which is significant for several biochemical applications. The technique is studied extensively using experiments and modelling. Several performance parameters of this heating technique were compared with a standard microheater through experiments and simulation. For the presented technique, the substrate near the droplet was cooler in comparison to the microheater. This will reduce parasitic heating of nearby droplets. A comprehensive study regarding the optimization of the geometrical parameters and the capability to heat solutions to higher temperatures using lower voltage and higher frequency were also performed using simulations. As conventional EWOD electrodes are used for heating the liquid, separate microheaters are not required. This significantly simplifies design and allows us to heat any droplet at any location on the chip. This on demand reconfigurability of droplet heating is the primary benefit of this technique. To establish the abilities of our suggested method, two biochemical experiments were demonstrated.

我们演示了一种通过使用高频高压交流信号来加热常规EWOD电极上的水滴的新技术。在高激励频率（10–1000 kHz）下，由于液滴内部的欧姆电流产生的焦耳热，液滴温度会升高。使用这种直接加热技术，我们能够达到93–94°C的温度，这对于几种生化应用而言都是非常重要的。使用实验和建模对该技术进行了广泛研究。通过实验和仿真，将该加热技术的几个性能参数与标准的微型加热器进行了比较。对于所提出的技术，与微加热器相比，液滴附近的基板温度较低。这将减少附近液滴的寄生加热。还使用模拟对几何参数的优化以及使用较低的电压和较高的频率将溶液加热至较高温度的能力进行了全面研究。由于常规的EWOD电极用于加热液体，因此不需要单独的微型加热器。这大大简化了设计，并允许我们加热芯片上任何位置的任何液滴。液滴加热的按需可重构性是该技术的主要优势。为了建立我们建议的方法的能力，论证了两个生化实验。不需要单独的微型加热器。这大大简化了设计，并允许我们加热芯片上任何位置的任何液滴。液滴加热的按需可重构性是该技术的主要优势。为了建立我们建议的方法的能力，论证了两个生化实验。不需要单独的微型加热器。这大大简化了设计，并允许我们加热芯片上任何位置的任何液滴。液滴加热的按需可重构性是该技术的主要优势。为了建立我们建议的方法的能力，论证了两个生化实验。