The basic tool of most microfabrication technology is photolithography. Initially, most photolithographic processes were conducted in silicon and these well-developed technologies were directly derived from the semiconductor industry. Recently, diverse non-silicon-based LOC fabrication methods have been developed. The biggest change in microfabrication has occurred in the materials used. In silicon technology, the main materials were silicon wafer, glass, photoresistor and metal which are excellent materials for mass production of integrated circuits. However for biomedical applications these materials and the fabrication processes have some limits due to: (1) the biocompatibility is not fully proven, (2) the cost of material is high, and (3) the fabrication process requires complicated facilities.

To address these limits, diverse microtechnologies employing several materials have been developed. As representative non-silicon materials, several polymers, such as poly(dimethylsiloxane) (PDMS), poly(methyl methacrylate) (PMMA), and cyclo-olefin copolymer (COC), have been used to construct a microstructure. In addition, biological material such as proteins, cells, and antigens can be used as micropatterning material to create biologically relevant patterns on the surfaces of substrates and this technology provides new capabilities for cell biology, the production of biosensors, and tissue engineering.

Recently, the assembly of biohybrid materials from engineered tissues and synthetic polymer thin films was done to perform biomimetic tasks (e.g. tissue based robot) by varying tissue architecture, thin-film shape, and the electrical-pacing protocol. In addition, diverse fabrication methods (e.g. softlithography, stereolithography, in situ polymerization, etc.) and devices (e.g. scanning tunneling microscope, deep reactive ion etching, etc.) have been developed for use in microfabrication technology.

Experimental techniques and associated technology in biology laboratories are evolving to handle small quantities of samples more efficiently and Lab-on-a-Chip (LOC) devices are becoming more widespread. It is becoming increasingly important for all biologists to gain a basic understanding of the technology of the microfabrication process.

from Sang-Hoon Lee (2009) in Lab-on-a-Chip Technology: Fabrication and Microfluidics

Bibliography:

1. Lab-on-a-Chip Technology: Fabrication and Microfluidics
2. Lab-on-a-Chip Technology: Biomolecular Separation and Analysis

Labels: in situ polymerization, microfabricationphotolithography, softlithography, stereolithography