Gray-scale photolithography using microfluidic photomasks

摘要: The ability to produce three-dimensional (3D) microstructures is of increasing importance in the miniaturization mechanical or fluidic devices, optical elements, self-assembling components, and tissue-engineering scaffolds, among others. Traditional photolithography, most widely used process for microdevice fabrication, ill-suited 3D because it based on illumination a photosensitive layer through “photomask” (a transparent plate that contains opaque, unalterable solid-state features), which inevitably results features uniform height. We have devised photomasks light-absorbing are made fluids. Unlike conventional photomasks, opacity photomask can be tailored an arbitrary number gray-scale levels, their spatial pattern reconfigured time scale seconds. Here we demonstrate inexpensive fabrication photoresist patterns contain multiple and/or smoothly varying heights. For given microfluidic photomask, developed predicted as function dye concentrations dimensions. selected applications, offer low-cost alternative present photolithography approaches.