Patent ID: 6577432
Filing Date: 2003-06-10
Classification: G02B

Abstract:
A microstructure to interact with electromagnetic waves, comprising:a microfabricated substrate comprising a base portion and a two-dimensional array of pockets on the base portion, each pocket having a sidewall, the sidewall having an inner side defining a cavity, the cavity having a bottom from which the inner side extends to a uniform height and a top opposing the bottom, the bottom being fluidly sealed, the inner side not enclosed at the top of the cavity but leaving an opening suitable for placing particles in each pocket from above, the bottom of the pockets being integral with the sidewall of the pockets; a plurality of optically anisotropic particles placed in the pockets from above, the placement of the particles resulting in a layer of the particles with at least two particles in each of substantially all pockets, and when so placed, the particles being rotatable; and a cover layer transparent to an electromagnetic wave laid across the two-dimensional array of pockets to seal the particles within the cavities, wherein: the microstructure is a visual display apparatus; the pockets are positioned close to each other and each pocket shares boundaries with other pockets adjacent to it, the geometric shape of the shared boundaries and the geometric shape of the inner side of each pocket being optimized to conform a closely packed pattern of the particles placed within the pockets; and the bottom of each pocket is contoured, forming a plurality of recesses, each recess receding from a substantially uniform recess height, the recess height being lower than the sidewall of the pocket, each recess being suitable for positioning one particle without substantially interfering the other particles positioned on the adjacent recesses.