Heated atomic force cantilever closed loop temperature control and application to high speed nanotopography imaging

This paper reports closed loop temperature control of a heated atomic force microscope cantilever and its application to thermal topography imaging. Closed loop feedback implemented in analog circuitry maintains cantilever temperature with 1.73 °C accuracy and 0.076 °C precision at 1 MHz bandwidth. The cantilever can respond to changes in temperature set-point within 16.5 μs, enabling thermal topography imaging at 500 μm/s, which is a 50× increase over previous work. We demonstrate how the cantilever thermal signal can be used in place of the traditional optical tip height sensing in order to image surfaces. The temperature control architecture can be scaled to large arrays of heated cantilevers without loss in bandwidth.