Search

We demonstrate that ultrathin (thickness below 1 μm) elastomeric stamps, directly fabricated on rigid substrates can be reliably used in microcontact printing (μCP), showing enhanced mechanical properties with respect to the thicker ones commonly utilized. Macroscopic distorsion (due to thermal expansion and external stress) and microscopic effects such as the membrane relaxation in wide unsupported areas are drastically reduced. A mix and match process (optical lithography followed by μCP) performed with submicron overlay accuracy proves the reliability of the present approach and its applicability to multilevel production processes.

We have developed a lithography process which originates from imprint lithography and offers advantages over it. Unlike imprint lithography, not only the sample but also the mold is covered with a thermoplastic polymer. The mold and sample are brought into contact, pressed together and heated above the glass transition temperature of the thermoplast, causing the two polymer layers to become bonded (glued) together. A special treatment of the mold and sample surface causes the polymer film to stick only to the substrate after cooling. The bonding occurs at pressures and temperatures lower than those usually applied in imprint technology, and eliminates problems in conventional imprint technology that are related to lateral transport of the polymer.

Recently, there has been growing interest in sensors based on frequency shift detection of mechanical resonators, that has led to extremely sensitive diagnostic methods for medicine and biology. Here the authors propose and demonstrate a strategy capable of detecting the presence of a few macromolecules, which uses an asymmetrical cantilever structure of several microns in size, operated at room temperature, and under ordinary vacuum conditions. The idea is to detect the presence of one or more molecules by detecting the mechanical cross-talk induced by the molecular link between a short cantilever and an array of longer cantilevers facing the short one. (c) 2007 American Institute of Physics.