Abstract: Method for casting a continuous cylindrical polymer stamp. The method includes depositing a first layer of a fluid polymer on the inside of a rotatable drum and rotating the drum for a selected time and at a selected angular velocity. The polymer is cured to produce a uniform datum surface. A second layer of polymer is deposited on the first layer in the drum and the drum is rotated until solvent in the polymer has evaporated thereby forming a stable layer. The polymer is selectively exposed and developed to create a desired pattern. Thereafter, a polymer precursor is deposited on the patterned second layer and the polymer precursor is allowed to cure while the drum is rotating to produce a cured stamp. The cured stamp is removed from the drum.

Abstract: Stamp for microcontact printing. The stamp includes a bulk portion having first and second surfaces, the first surface including a pattern of features to be transferred and the second surface including a different pattern of features. The features on the second surface have a lower stiffness than the features on the first surface. The dual-face stamp design of the invention provides an alternative location for dimensional errors to be absorbed, making microcontact printing a more robust production process.

Abstract: A practical implementation of a flexible and transparent capacitive sensor is disclosed. The results show that, while PDMS is an inherently nonlinear material, linear behavior with minimal hysteresis can be obtained over an appropriately small range of operation. Moreover, high resolution has been achieved during these tests.

Abstract: Precision embossing press. The press includes a rigid symmetric box frame and upper and lower parallel embossing platens mounted within the box frame for movement towards one another to provide an embossing compressive force on a work piece between the platens while maintaining parallelism between the platens. A thermal system controls platen temperature to heat the work piece for embossing and to cool the work piece for de-molding. A pneumatic actuator moves the lower platen toward the upper platen to emboss the work piece. A closed loop control system employing feedback and feed forward control loops controls platen temperatures and embossing force.

Abstract: Stamp for microcontact printing. The stamp includes a bulk portion having first and second surfaces, the first surface including a pattern of features to be transferred and the second surface including a different pattern of features. The features on the second surface have a lower stiffness than the features on the first surface. The dual-face stamp design of the invention provides an alternative location for dimensional errors to be absorbed, making microcontact printing a more robust production process.