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Chao-Min Cheng — 2006-07 Fellow

Chao-Min Cheng photo

The ability to create realistic systems at the micro- and nano-meter scale requires novel concepts for building systems. These systems include artificial vasculature for tissue engineering and microlens for visualization schemes that are smaller than insect eyes. The ability to create these complex three-dimensional systems in fabrication processes is very challenging since planar limited mask-based processes often dictate the final architecture of a device. To fabricate complex architectures at the nanometer and micrometer size scale, there are many techniques which can be leveraged. Physics based techniques have created a revolution in the computer chip industry and have been further developed in sophisticated applications using silicon and glass for building traditional integrated circuits (IC) through processes including photolithography, etching techniques, and deposition. These techniques can be used to develop complex material configurations. These processes though often have limitations including fabrication cost, clean-room conditions, labor intensive processes, and material technologies. Thus, alternate technologies have evolved including soft lithography, nanoimprint lithography, microcontact printing, and capillary lithography. One of the common features of many of these techniques is that they utilize a mold of either silicon or polymer, which is brought into contact with an underlying mask containing the essential fabricated features. These systems require access to specific equipment and also significant fabrication time for each component. The original process of hard lithography has been augmented with the advent of soft lithography, which allowed a master mold to be developed and then it is used to produce many copies with polydimethylsiloxane or other polymers. Although these are well established methods, due to their limitations, we propose two novel methods that can control the geometry, mechanical strength, and biocompatibility.

The overall goal of this work is to create novel methods that will provide us the ability to specifically fabricate three-dimensional architectures. These will be applied to inorganic systems, but to probe their potential alternate applications, we will also investigate their interactions with biological systems. This can be accomplished through spanning a multidisciplinary set of research including engineering, physics, biology, and material science. The specific objectives are:

Objective 1: Develop novel approaches to create controlled complex biocompatible structures through photocurable chemistry in both two- and three-dimensions.

Objective 2: Develop thermally adjustable biomimetic lenses.