Researchers at the Australian National University have found a way to make microscope probes 20 times more sensitive and able to identify forces as tiny as the weight of a virus. The technique requires laser beams to cool a nanowire probe ti minus 265 degrees Celsius. According to Ben Buchler from the ANU Research School of Physics and Engineering, the level sensitivity is accurate enough to detect the weight of a virus that is 100 billion times lighter than a mosquito.
The research has obvious medical and practical implications, as it can enhance the resolution of atomic-force microscopes. Atomic-force microscopes obtain a very precise measurement of the microscoping characteristic of a specimen by scanning a wire probe over the surface. The probes are, however, susceptible to vibration. With this new technique the vibrations can be stopped through cooling. Ping Koy Lam, a professor with ANU explains that at room temperature the probe vibrates interfering with the accuracy of the measurement. The lasers can stop the vibration. The lasers make the probe warp and move due to the heat but the movement can be controlled and the scientists were able to manipulate the warping to counter the thermal vibration of the probe.
The probe, however, can not be operated while the laser is on, it has to be switched off first and measurement needs to be taken before the probe warms up again.