Biomimetic Optical Sensing Systems (BOSS)

While conventional optical sensing devices such as CCD and CMOS imagers are planar in geometry, the imagers in nature are different. Fruit flies have spherical compound eyes and human has spherical retinal. The project aimed to develop a biomimetic optical sensing system (BOSS) by combing the state-of-the art IC fabrication technologies and the elastomer engineering techniques. We have demonstrated the following proof-of-concept works:

1. Post-CMOS processing compatible fabrication methods to integrate photodetectors with the elastomer.

2. Electrical connection methods on a tunable spherical membrane using MEMS flexure.

The project is currently seeking funding to support prototyping the imager using PDMS elastomer with integrated MSM Poly-Si photodetectors.

SEM picture of the fabricated device when there is no pneumatic pressure applied; inset: SEM picture of an Metal-Semiconductor-Metal (MSM) Photodetector array before integration with the elastomer membrane.

SEM picture of the fabricated device under 50KPa applied pressure. To acquire SEM images, UV curable polymer was injected to pump the membrane. The device was then cured under a UV lamp for 12 hours to fix the shape at this pumping pressure

References:

S. R. Quake and Scherer. A ·From micro- to nanofabrication with soft materials,· Science. vol. 290, 2000, pp. 1536·1540.

N. Chronis, G. L. Liu, K. Jeong and L. P. Lee, ·Tunable liquid-filled microlens array integrated with microfluidic network,· Optics Express, vol. 11, 2003, pp. 2370-2378.

S. P. Lacour, S. Wagner, Z. Huang and Z. Suo, ·Stretchable gold conductors on elastomeric substrates,· Applied Physics Letter, vol. 82, 2003, pp. 2404-2406.