Two-dimensional optical micro-scanner on silicon technology

A two-dimensional optical micro-scanner, which main components are two mobile flat and a concave micro-mirrors, is designed such that, all optical components can be fabricated on the same substratum. The optical parameters, which physical dimensions are between 50 and 500 μm, are obtained within the geometrical optics. The optical performance is evaluated by means of the MTF and Rayleigh resolution criteria, given 80% of modulation for a frequency of 8 cycles/mm with a Gaussian source, the resolution limit is 30 μm.     

Ambipolar a-SiGe:H thin-film transistors fabricated at 200 °C

In this paper, we study the ambipolar behavior of a-SiGe:H thin-film transistors fabricated at 200 °C. A subthreshold slope and an on/off current ratio of 0.34 V/DEC and 10⁵, respectively, were measured for the n-type region, whereas values of 0.15 V/DEC and 10⁴ for were measured for the p-type region. We also obtained the characteristic energies for the deep localized states of the a-SiGe:H film, the flat-band voltages, and threshold voltages among other device parameters for the ambipolar thin-film transistors.     

Size-Exclusion "capture and release" separations using surface-patterned poly(N-isopropylacrylamide) hydrogels

Micrometer-scale poly(N-isopropylacrylamide) (poly-NIPAAm) hydrogel monolith patterns were fabricated on solid surfaces using soft lithography. At sufficiently high aspect ratios, the hydrogel monoliths swell and contract laterally with temperature. The spaces between the monoliths form a series of trenches that catch, hold, and release appropriately sized targets. A series of poly-NIPAAm monoliths were fabricated with dry dimensions of 40 microm height, 12 microm diameter, and a spacing of 12 microm between monoliths. Above the lower critical solution temperature (LCST), the monoliths collapse to their dry dimensions and the spacing between monoliths is 12 microm. Below the LCST, the monoliths swell by 70% in the lateral direction, reducing the gap size between monoliths to 3 microm. The potential use of the hydrogel monoliths as size-selective "catch and release" structures was demonstrated with a mixture of 6 and 20 microm polystyrene microspheres, where the 6 microm diameter particles were selectively concentrated and separated from the larger particles.