Laser Cutting for Epidermal Microfluidic Sequential Sweat Sampling Patches
The human sweat contained a rich array of biomarkers,and the concentrations closely linked to the individu-al's physiological and health status.The epidermal microfluidic patches presented an ideal platform for sweat sampling.The sequential microfluidic sweat sampling utilizing capillary burst valves allowed the temporal storage of sweat in different res-ervoirs,which enabled the analysis of sweat information from distinct time periods,and it was a commonly employed meth-od in microfluidic sweat sampling.However,traditional time-sequential microfluidic sweat sampling and sensor processing relied on soft lithography,which had higher processing costs and longer production cycles.The laser cutting of microfluidic patches offered advantages in terms of rapidity,low-cost,high design flexibility and so on.Nevertheless,small-sized micro-channels was obtained with difficulty with laser-cut double-sided adhesive tapes,which limited the application of this tech-nology in fabricating sequential sweat sampling microfluidic patches.We optimized the structure design of sequential sam-pling microfluidic devices for laser cutting,and validated the sequential sampling capability of the manufactured patches through experiments involving liquid collection of a injection pump based and sweat sampling on human skin.The proposed structural design and processing approach significantly reduced the manufacturing costs of sequential sweat sampling mi-crofluidic patches,enhanced processing efficiency,and improved device design flexibility.