Micropatterning and Integration of Electrospun PVDF Membrane Into Microdevice

Abstract

This article reports a novel work on the fabrication of microarrays of electrospun Poly(vinylidene fluoride) (PVDF) membrane for MEMS and energy harvesting applications. Micropatterning of PVDF membrane is an essential step in fabrication process in order for the sample to be integrated in microelectromechanical systems. The high $\beta $ -phase fraction of PVDF membranes was successfully synthesized by one step electrospinning technique. A new fabrication process for micropatterning of electrospun PVDF membrane is being proposed using dry reactive ion etching. Oxygen plasma was chosen as the feeding gas in investigation for high etching rate in PVDF microstructure fabrication process. Micropatterning dimensions of 200/500/ $200~\mu \text{m}$ with the height of over $50~\mu \text{m}$ and etching rate of $2~\mu \text{m}$ /min were achieved in this work. Details of the fabrication process are discussed. High etching rate of patterning process with the selected parameters can be achieved on the electrospun PVDF membranes. This work has demonstrated successful micropatterning and integration of PVDF membrane into MEMS, thus open the possibilities for various application such as for sensors and actuators utilizing polymer membrane. We have validated the capability of the micropatterned device as energy harvester in producing an open circuit voltage density of 1.42 $\text{V}\cdot \text{m}^{{-2}}$ at temperature of 310.15 K and wind speed of 1 $\text{m}\cdot \text{s}^{{-1}}$ . [2019-0180]