(391d) Electrostatically Actuated Microvalves Fabricated with Soft Lithographic Techniques for Integrated Biological Microsystems

As efforts continue to create biological microsystems with higher degrees of integration, improving microvalve technology will be critical. ?Quake?-style pneumatic microvalves have become prevalent in the field due to their straight forward soft-lithographic fabrication [1]. Thousands can be created in parallel and integrated into complex networks with high number density. However, these microvalves require several encumbering ancillaries, including a pressurized gas source, an array of solenoid valves, and computerized controls, which limit portability. Maharbiz et al. created an electrostatic microvalve with less cumbersome ancillaries that retains similar performance characteristics [2, 3]. The tradeoff is a complex fabrication process that includes high-temperature annealing, photoresist patterning, metal evaporation, and etching.

We report the design, fabrication, and testing of an electrostatically actuated microvalve made exclusively with soft-lithographic techniques. Our novel fabrication significantly reduces the complexity of fabrication and integration. The valve comprises an elastomeric membrane embedded with conducting nanoparticles and suspended above a lower electrode with the aid of a support structure. We have developed an analytical model that identifies several parameters affecting actuation potential, including distance between the electrodes, diameter of the microvalves, and elastic modulus of the elastomer. Additionally, the shape of the membrane's support structure influences actuation potential. We will present work to optimize the valve design by altering the geometry of the support structure, a comprehensive study of valve isolation pressures with different fluids, and integration of the valve into a biomedical device.

REFERENCES

1. M. A. Unger, H. P. Chou, T. Thorsen, A. Scherer and S. R. Quake, Science 2000, 288, 113-116.

2. T. Bansal, M. P. Chang and M. M. Maharbiz, Lab Chip 2007, 7, 164-166.

3. M. P. Chang and M. M. Maharbiz, Lab Chip 2009, 9, 1274-1281.