Title:Unconventionl micro-fabrication schemes for the realization of three dimensional, non-planar Polydimethylsiloxane structures and their applications
Speaker: Jungwook Paek, ECpE Graduate Student
Advisor: Jaeyoun Kim, Associate Professor
Abstract: Here, we first demonstrate a new, unconventional fabrication scheme for 3D-networked, cylindrical MF channels. The scheme allows facile realizations of highly curved 3D MF channel trajectories, proper MF junctions, and internally looped MF channels. The diameter of the MF channels can be well below 100 μm. It also allows the formation of tapered junctions and locally dented MF channels, which will especially benefit vaso-mimetic applications. Utilizing only water-based, low-temperature processes, our scheme is ideal for rapid prototyping of LoCs without fume-hoods or clean room facilities. Secondly, we present another unconventional soft-lithography fabrication scheme which enables the realization of PDMS micropillars exceeding 2400 m in height and 100 in aspect-ratio through the combined utilization of the direct drawing and the in situ heating. It also allows automatic integration of microspheres at the tips of the micropillars in a self-aligned fashion. As a validation of the structure’s utility for acoustic sensing, we configure it into the cricket-inspired air-flow sensors, in which the micropillars and microspheres function as flexible upright waveguides and self-aligned reflectors, respectively. High-level bending of the micropillar under air-flows and its optical read-out enable mms-1-scale sensing resolution. This new scheme, which uniquely integrates high aspect-ratio elastomeric micropillars and microspheres self-aligned to them, will widen the scope of soft material-based microdevice technology.