Direct Write Patterning of Microchannels

Microchannel-based master molds or final devices are typically produced using a series of resist deposition, exposure, development and etching steps. These steps can then be repeated to create multi-layer fluidic structures. Traditional fabrication of these devices requires the use of a physical mask for the photolithographic exposure process. In the research and development environment, where designs are constantly undergoing changes, or in rapid-time-to-device applications, this can be a costly and time-consuming practice. We have employed a novel, micron-scale resolution maskless photoimaging/patterning tool that permits the creation of small, arbitrary features. This microdevice printer is useful for constructing fluidic channels, devices, structures and packages utilizing any photoimageable or photoreactive material that can be applied towards fabrication of integrated microfluidic-based systems. The fabrication technology can provide features down to 20 microns simultaneously over a 2×2 cm² field of view. Additionally, manual stitching techniques can yield unlimited field-of-view for large area fluidic patterns with high-resolution elements. The instrument relies on the use of microoptics and spatial light modulation to create the required 2D aerial image for photoimprinting. The instrument creates mask-free designs on planar and curved surfaces and has been applied to a variety of materials, including metals, ceramics, organic polymers and semiconductors. We have demonstrated the utility of the instrument for creating mechanical, optical, fluidic and electronic components and combinations that would form the basis of integrated microfluidic systems, microanalytical systems and micrototal analysis systems (uTAS). We have also created fluidic channels having structures integrated within the channel geometry. The technology has widespread applications in the MEMS, bioMEMS, microcooling technologies and sensor markets. A further extension of the technology is the application of the direct printer to rapid prototyping of microchannels and minichannels for fuel cells, microrefrigerators, heat exchangers, and biomedical devices.