Photo-Induced Fabrication Technology for 3D Microdevices

Abstract

This chapter introduces photo-induced fabrication technologies for 3D MEMS devices. At first, we introduce principles of 3D photo-induced fabrication focusing on common aspects of photo-induced cross-linking and range of applicable materials. Then, we examine four technologies and their outcome of applications in detail where fabricated feature sizes decrease and resolution increases with progression of this chapter. (1) Microstereolithography enables a layer-by-layer fabrication of 3D devices, which find application in coaxial microfluidics and device fabrication in the presence of cells. (2) In situ photolithography is a 3D device fabrication with a pre-polymer solution inside microfluidic devices enabling fabrication of 3D structures inside microfluidic channels. (3) Flow lithography applies the concept of flowing pre-polymer material inside a microfluidic device in order to fabricate variously shaped microparticles for self-assembly or potential use as drug delivery systems. (4) Direct laser writing exposes focused laser light moved by computerized piezo actuation through pre-polymer medium enabling to structure with nanometer-sized feature sizes and constructing materials with special optical or mechanical properties as well as 3D devices for cell culture studies. The application of the achieved 3D devices ranges from microfluidic elements over bioMEMS devices constituting of analytical tools, cell culture conservation, and cell culture studies to biomedical application suitable for implants.