Long Distance Transport of Microdroplets and Precise Microfluidic Patterning Based on Triboelectric Nanogenerator

Here, a smart microfluidic system that can realize both long distance transport of micro-/nanodroplets and precise patterning of microfluidics is designed based on triboelectric nanogenerator (TENG) and a photocontrollable adhesion surface (PCAS). The high output voltage from TENG can eject a microdroplet to a maximum distance of 640 mm (a maximum distance/diameter ratio of 300), while TENG can also manipulate the microdroplet under a thick dielectric layer (2 mm). Meanwhile, water adhesion as well as contact angle of the PCAS changes significantly with a short period of UV treatment and thus it can help to capture the moving microfluidics at the designated position. Moreover, microfluidic patterning with a variety of patterns and arrays on this PCAS can be obtained by using UV imprinting and the combination of TENG and PCAS can achieve an effective self-powered microfluidic patterning system. Finally, a tunable gripper probe for 3D transport of microdroplets is demonstrated as another application of TENG and PCAS. These smart microfluidic systems based on TENG and PCAS have excellent applicability for many fields, such as drug/cell delivery, controllable chemical reaction for liquid testing, and production of microdroplets.