Radio frequency cantilever-free scanning probe microscopy.

This article focuses on the development of a cantilever-free scanning probe microscopy (SPM) imaging system based on contact resistance detection using radio frequency (RF) reflectometry. The system employs a conductive carbon black-polydimethylsiloxane (CB-PDMS) elastomeric tip and a custom-built RF reflectometry setup to achieve sensitive, high-bandwidth detection of contact resistance changes, enabling nanoscale topography imaging with a demonstrated vertical resolution of 230 nm and a detection bandwidth of approximately 8.5 MHz. The approach offers advantages such as facile tip fabrication and a simple mechanism without the need for feedback control, which supports potential scalability to massively parallel probe arrays for high-throughput measurements. Remaining challenges include improving the spatial homogeneity of conductive elastomer tips for enhanced lateral resolution and developing multiplexing techniques for practical operation of parallel probe arrays.