A Parylene-C Microplate Fabrication for Determining Cell Traction Forces

Abstract

In order to study the CTFs in three-dimensional state, a Parylene-C microplate was fabricated on glass substrate by vapor deposition of Parylene-C film, and subsequent patterning by photolithography and etching using the micro-electromechanical systems (MEMS) technology. For Parylene-C etching process, its low etching rate accuracy and poor etching uniformity make it difficult to precisely etch 2.9 μm-deep and 100 nm-thick grooves on 3 μm thick Parylene-C patterns. In this paper, through design optimization and process improvement, the process of one deposition step and two etching steps was changed to the process of two deposition steps and two etching steps, and the corresponding thickness groove was formed by the second direct deposition of 100 nm-thick Parylene-C film and etching the area outside the groove. The Parylene-C thin film was patterned accurately and efficiently. Finally, a pair of Parylene-C square patterns with thickness of 3 μm, side length of 50 μm, and spacing of 5 μm were obtained. The Parylene-C link with a thickness of 100 nm was formed between the square patterns. After the fabrication of the microplate, the surface of the glass substrate was treated by acyloxyethyl phosphocholine polymer coating. Fibroblast was seeded on Parylene-C microplate. The results show that Parylene-C microplate had good biocompatibility, and single fibroblast grew well on the microplate. The connection between square patterns had good flexibility and deformability, and the microplate was folded easily by touching the microplate gently with a micro-needle. The microplate can provide a new means for measuring the stretch force of cells in three-dimensional state.

Keywords

• cell traction forces
• parylene-c microplate
• mems micro-fabrication
• cell culture