 Scientists around Daniel Rugar and John Mamin at the IBM research laboratories in Almaden have been the pioneers in using heated AFM (atomic force microscope) probes for the modification of surfaces.In 1992, they used microsecond laser pulses to heat AFM tips to write indents as small as 150 nm into the polymer PMMA at rates of 100 kHz.In the following years, they developed cantilevers with resonance frequencies above 4 MHz and integrated resistive heaters and piezoresistive sensors for writing and reading of data.