Fabrication of photothermally driven micropump using SU-8/Cu composite

Lab-on-a-chip (LOC) devices, which integrate laboratory functions, such as mixing, separation, and detection of samples onto a single chip, have been actively developed. A key component of LOC systems is the micropump, which is responsible for fluid transport. In this study, we propose a photothermally driven micropump using an SU-8/Cu composite, which simplifies the fabrication process and can be actuated by the excitation light of observation systems, such as inverted microscopes. The fabricated micropump exhibited a linear increase in the pumping volume with increasing irradiance. A maximum pumping volume of 2.68 µ l was achieved at an excitation light irradiance of 1.54 W cm −2 . Furthermore, the reproducibility of both pumping and aspiration volumes was confirmed during the ON–OFF cyclic experiment. The pumping pressure also increased with irradiance, reaching a maximum value of 329 ± 20 Pa at 1.54 W cm −2 . These results suggest that the proposed device can be used for reagent delivery and observing and evaluating biological responses, with potential applications in the biomedical field and beyond.