Biomimetic Soft Polymer Microstructures and Piezoresistive Graphene MEMS Sensors Using Sacrificial Metal 3D Printing

• DOI: 10.1021/acsami.0c21295
• Publication Date: 2021-01-04T20:16:30Z
• Authors: Amar M. Kamat; Yutao Pei; Bayu Jayawardhana; Ajay Giri Prakash...
• Keywords: Polydimethylsiloxane; Piezoresistive effect; Soft Lithography

Recent advances in 3D printing technology have enabled unprecedented design freedom across an ever-expanding portfolio of materials. However, direct soft polymeric materials such as polydimethylsiloxane (PDMS) is challenging, especially for structural complexities high-aspect ratio (>20) structures, microfluidic channels (∼150 μm diameter), and biomimetic microstructures. This work presents a novel processing method entailing thin-walled sacrificial metallic mold, polymer casting, acidic etching the mold. The proposed workflow enables facile fabrication various complex, bioinspired PDMS structures (e.g., double helical embedded inside pillars) that are difficult or impossible to fabricate using currently available techniques. further infused with conductive graphene nanoplatelet ink realize two flexible piezoresistive microelectromechanical (MEMS) sensors (a flow/tactile sensor dome-like force sensor) sensing elements. MEMS integrated into Philips 9000 series electric shaver demonstrate its application "smart" consumer products future. Aided by current trends industrialization miniaturization metal printing, shows promise low-temperature, scalable, cleanroom-free technique fabricating polymeric, sensors.