Design and development of nanoimprint-enabled structures for molecular motor devices

Devices based on molecular motor-driven cytoskeletal filaments, e.g., actin filaments, have been developed both for biosensing and biocomputational applications. Commonly, these devices require nanoscaled tracks for guidance of the actin filaments which has limited the patterning technique to electron beam lithography. Thus, large scale systems become intractable to fabricate at a high throughput within a reasonable time-frame. We have studied the possibility to fabricate molecular motor-based devices using the high throughput, high resolution technique of nanoimprint lithography. Molecular motor-based devices require wide open regions (loading zones) to allow filaments to land for later propulsion into the nanoscale tracks. Such open zones are challenging to fabricate using nanoimprint lithography due to the large amount of material displaced in the process. We found that this challenge can be overcome by introducing nanoscaled pillars inside the loading zones, into which material can be displaced during imprint. By optimising the resist thickness, we were able to decrease the amount of material displaced without suffering from insufficient filling of the stamp. Furthermore, simulations suggest that the shape and positioning of the pillars can be used to tailor the overall cytoskeletal filament transportation direction and behaviour. This is a potentially promising design feature for future applications that however, requires further optimisations before experimental realisation.