An optical detection low temperature atomic force microscope at ambient pressure for biological research

A low temperature atomic force microscope, based on the optical lever detection method and operated in liquid nitrogen vapor at ambient pressure, has been constructed. The experimental results show that atomic resolution images can be obtained on both mica and highly oriented pyrolytic graphite at temperatures down to 79 K with sufficient thermal stability. In liquid nitrogen vapor, no surface contamination was observed after many hours of continuous operation, which demonstrates that such an approach is ideal for biological applications for its lower cost and easy maintenance.