Innovative MEMS Cantilever for Low Temperature Atomic Force Microscopy
As part of a collaboration between the University of Technology Sydney and Justus Liebig University Giesen a proof of concept for an active microelectromechanical system (MEMS) microcantilever with integrated piezoelectric sensing was introduced and its capability to perform high-resolution non-contact atomic force microscopy (AFM) and scanning tunneling microscopy (STM) at low temperatures on an atomically flat Au(111) surface was demonstrated. This innovation addresses limitations of conventional qPlus tuning fork sensors, which are currently the state of the art for low-temperature AFM under ultra-high vacuum conditions. The new MEMS cantilever design offers a stepped rectangular geometry with closely spaced higher eigenmodes, allowing for multifrequency imaging schemes. The ability to tune the design parameters, such as dimensions, geometry, spring constant, and resonant frequency in wide ranges, offers flexibility and potential for further optimization such as effective excitation and high sensitivity at higher normal or torsional eigenmodes.
Future work aims to improve the noise performance and deflection sensitivity of the device, as well as to explore the use of higher eigenmodes for enhanced imaging capabilities. This opens possibilities for the development of advanced AFM techniques, potentially leading to improved imaging speed, higher sensitivity, and expanded application areas in surface science and nanotechnology.
Original publication: M. G. Ruppert, M. Wiche, A. Schirmeisen and D. Ebeling. Low temperature multimode atomic force microscopy using an active MEMS cantilever. Nanoscale 17, 10600 (2025) (cover article). https://doi.org/10.1039/D4NR04169K
