Authors: D. de Roover, L.M. Porter II, A. Emami-Naeini, J.A. Marohn, S. Kuehn, S. Garner and D.D. Smith
Affilation: SC Solutions, Inc., United States
Pages: 40 - 43
Keywords: MRFM, cantilever control, digital, FPGA
An all-digital cantilever controller for magnetic resonance force microscopy (MRFM) was developed through a close collaboration between SC Solutions, Cornell University, and the U.S. Army Research Laboratory. The advantage of an all-digital controller is its absence of thermal drift, as well as its great tuning flexibility. This versatile controller is comprised of a Field Programmable Gate Array (FPGA) connected via a low-latency interface to an analog input, an analog output, and a Digital Signal Processor (DSP) with additional analog outputs. Performance of the controller was demonstrated in experiments employing ultrasensitive silicon microcantilevers fabricated at Cornell University’s Nanoscale Science and Technology Facility. The all-digital cantilever controller successfully measured millihertz shifts in the resonance frequency of these ultrasensitive microcantilevers on a millisecond timescale. Independently, a noise floor of 40 microHerz was measured for this controller.