Nanowire-based Miniaturized Mechanical Transducers Designed for Surface Force Sensing

• Applicant: Professor Dr.-Ing. Sergej Fatikow
• Subject Area: Measurement Systems ; Microsystems
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 509134333

Nanoscale material systems continue to revolution all facets of the technology sector, from microelectronics to biomimetic adhesives. To expedite further exploitation of nanoscale systems, improved techniques for detecting their surface forces are essential. The current benchmark technique is to implement a microcantilever as a miniaturized mechanical transducer within an atomic force microscope in which the surfaces forces acting on the transducer are transformed into a displacement. The displacement is then ‘read-out’ by the optical beam deflection approach. In order to improve the force sensitivity and versality of the atomic force microscopy once must consider how to shrink down the mechanical transducer to the nanoscale. To do this, one can replace the ‘top-down’ fabricated microcantilever with a molecule-by-molecule synthesized nanowire. However, the deflection of such one-dimensional nanostructures can no longer be detected by the optical beam deflection approach and so alternative read-out strategies are required.This project aims to design, fabricate, and demonstrate nanowire-based miniaturized mechanical transducers with dedicated colloidal particle sensor elements for use in force sensing applications. Static deflection of the nanowire element will be read-out using high-resolution optical microscopy, whilst dynamic deflection will be read out using laser-based vibrometry. The highly compliant nanowire in combination with the idealized geometry of the colloidal particle is expected to provide a sensor with superior force sensitivity, precisely definable and tailorable surface interaction, as well as the versatility to characterise geometrically complex surfaces. Finally, the novel mechanical transducers will be applied to the surface characterization of non-planar and state-of-the-art nanoscale hierarchical structures provided by our collaborative partners. These tests are to clearly demonstrate the enhanced functionality of the transducers and their corresponding read-out strategies in applications where existing conventional atomic force microscopy is particularly lacking.

• DFG Programme: Research Grants