Research On Micro Fabrication Method Based On Flash Foam Stamp Lithography And Its Application

As the primary supporting technology for MEMS, fabrication of microstruc tures has attracted much interests from researchers and developers. Common mi crofabrication methods can be classified as follows:photolithography, chemical etching, LIGA, μHE, nanoimprinting, soft lithography and micro machining et al.Each method is advantageous for certain specific application.Whereas,duri ng the development of MEMS devices, it’s inevitable that a number of iterativ e processes have to be experienced.Designers want their prototype can be fabr icated as soon as possible so that follow-up analysis and testing can be done.h owever,the initial replication template of almost every microfabrication method must be fabricated by photolithography,it’s high cost and the long fabrication cycle will lead to the slow down of development process.This paper proposes a facile microfabrication method named flash foam st amp lithography(FFSL) based on daily used material flash foam(FF). In this pa per, we demonstrate that FF is a suitable and low-cost template for many micr o fabrication methods, such as micro casting and soft lithography. When FF is exposed with a desired pattern mask,the negative of the pattern is transferred to its surface and micro structures are formed.Concentrating on process research and its practical application, the main work of this paper includes:1. Feasibility verification and principle analysis.The feasibility of FFSL for the rapid fabrication of microstructure is verified. Mask material used in FFSL a nd its applicable occasions are discussed; the effects of exposure energy and exposure times on final results are studied and optimized using control vari ate method.2. Multi-scale structures for rapid processing.Multi-scale structures is usually fo und in MEMS,surface texture fabrication, biomimetic structure and so on. In this paper,we demonstrate that multi-scale micro structures can be manuf actured effectively by double exposure using the replacement of mask with FFSL.Skin textures is used as one case to demonstrate that structures with d ifferent depth can be fabricated by controlling grayscale of mask in single e xposure. As a result,FFSL shows considerable prospect in the field of cell biology and analytical chemistry.3. Exploration of application field of FFSL. Application of FFSL on manufactu re of μPADs and flexible circuits are studied, The whole process is simple and quick.Using patterned FFS as template to stamp directly on filter paper to make μPADs. The formed μPADs can be used for NO2- concentration a nalysis.Furthermore,flexible paper circuit can be made by firstly soaking μP ADs with hydrophilic channel and hydrophobic barriers in conductive ink an d then let it dry naturally.That can also be used tomake flexible micro-touch switch,3D LED lamp.