Polymeric Microcuboids Programmable for Temperature‐Memory


Microobjects with programmable mechanical functionality are highly desirable for the creation of flexible electronics, sensors, and microfluidic systems, where fabrication/programming and quantification methods are required to fully control and implement dynamic physical behavior. Here, programmable microcuboids with defined geometries are prepared by a template‐based method from crosslinked poly[ethylene‐co‐(vinyl acetate)] elastomers. These microobjects could be programmed to exhibit a temperature‐memory effect or a shape‐memory polymer actuation capability. Switching temperatures Tsw during shape recovery of 55 ± 2, 68 ± 2, 80 ± 2, and 86 ± 2 °C are achieved by tuning programming temperatures to 55, 70, 85, and 100 °C, respectively. Actuation is achieved with a reversible strain of 2.9 ± 0.2% to 6.7 ± 0.1%, whereby greater compression ratios and higher separation temperatures induce a more pronounced actuation. Micro‐geometry change is quantified using optical microscopy and atomic force microscopy. The realization and quantification of microparticles, capable of a tunable temperature responsive shape‐change or reversible actuation, represent a key development in the creation of soft microscale devices for drug delivery or microrobotics.
QR Code: Link to publication