武尾 正弘

Mixing is difficult in microfluidic devices due to the low Reynolds’ number. We proposed and demonstrated a surface-acoustic-wave (SAW)-based microfluidic system which can control the temperature by mounting a heater. This device has a hollow cylindrical reservoir made of resin on a piezoelectric substrate (LiNbO3), and the solution can be rotated by injecting SAWs from both sides, which are shifted parallel to the central axis of the reservoir. 0.75 W of power was supplied to the IDT to generate SAWs, and the temperature rise of the liquid was measured with a thermographic camera when 0 to 0.55 W of power was supplied to the heater. As a result, by mounting the heater on the SAW actuator, it was possible to uniformly raise the temperature of a 40 µL micro-liquid by 8 to 40 °C in about 80 seconds, demonstrating the usefulness of this heater-mounted SAW agitation device.