All-electric atomic force microscopy probes Atomic force microscopy (AFM) can be used to measure physical properties of materials with nanoscale resolution. EU-funded researchers have improved both resolution and speed of AFM systems, opening doors for a broad range of applications. Energy © Dr Ernest J. Fantner Current applications of AFM range from imaging biological samples, viruses and DNA, to evaluating the atomic orientation of polymers and crystals. AFM can capture features of objects and surfaces down to fractions of a nanometre. The minuscule signals generated from tiny interactions by a cantilever equipped with a sharp tip as it passes over the surface of a sample need to be handled carefully and magnified immensely. With EU funding of the project FALCON (Fast all-electric cantilever for bio-applications), an international consortium sought to increase the speed of AFM and extend its usability. It redesigned electro-optical components and brought an all-electric cantilever to market. Using nano-granular tunnelling resistors (NTR) manufactured with a maskless direct writing technique, the new technology promises to overcome limitations of optical detection. Specifically, FALCON established a fast and cost-effective manufacturing cycle for NTR sensor integration into cantilever on wafer level. The team conducted extensive tests to verify the NTR-based cantilever performance and confirm that large-scale processes deliver the same quality product as the initial lab trials did. Furthermore, development of an upgrade module for existing AFM systems will ensure that users do not have to scrap expensive existing systems to invest in something entirely new. The FALCON technology enables a step increase in performance compared to conventional cantilevers relying on optical detection to measure the deflection of a laser beam by the cantilever. With elimination of the need for lasers, it also provides greater flexibility of use in a broader range of applications. For instance, combining AFM with other microscopy techniques will allow correlated microscopy and open up unique characterisation possibilities on the nanoscale. Keywords Atomic force microscopy, nanoscale, cantilever, FALCON, laser beam
