Multifunctional nanomembranes self-assembled into compact rolled-up sensor–actuatordevices

Abstract

This paper reports on the functional principle for a rolled-up microdevice family providingthe possibility to realise electrical sensor and actuator functions which are applicable tomicrosystem techniques, in the field of physical measuring techniques, microfluidics andbiological–medical analytics. The fabrication of the roll-up devices is based ona strain-driven process converting a planar two-dimensional membrane into athree-dimensional functional element. For the realisation of these roll-up structures a broadspectrum of thin film technological approaches were used, which are well established. Thespecial feature of these advanced microdevices consists in the possibility to design thelatter’s inner surface using established additive or subtractive thin film techniques. Thetechnological route elaborated in the present work could possibly be used to realise a valvefor microfluidics thanks to the combined advantages of rolled-up devices andthe unique properties of temperature-sensitive hydrogels. Due to the thermaldecoupling of the processed microheaters from the supporting substrate the obtainedmicrodevices obtained are superior to conventional miniaturised planar devices in theirgeneral performance, especially in respect to the dynamical behaviour of thethermal properties. This is a prospective basis for the conceptual creation ofcombined sensor/actuator devices with tailored electrical and thermal properties.