Sharvari Panchbhai
Member • Aug 18, 2014
ANU Researchers Use Laser Cooling Technique In Atomic Force Microscope
Australian National University researchers from the School of Physics and Engineering have devised a new method to make atomic force microscope probes 20 times more sensitive by using laser beams which can cool a nanowire probe up to -265 degrees Celsius. This microscope is known for measuring diminutive structures and also the tiny forces between two molecules. The new technique helps the atomic force microscope to detect the weight of a virus that is 100 billion times lighter as compared to the weight a mosquito.
According to Ping Koy Lam, from the Research School of Physics and Engineering at ANU, the atomic force microscopes are extraordinarily sensitive while measuring the microscopic objects but the probe of the microscope which is 500 times finer as compared to human hair is often prone to vibration at room temperature. The vibrations are caused when the probe becomes warm. Moreover, these vibrations can distort the measurements. With a perspective of stopping the motion while taking measurements and improve the measuring capability of the microscope, the laser physicists of Quantum Optics Group focused lasers at the probe. They have tried to control the warping effect (effect related to distortion caused by thermal vibration of the probe).
As the laser affects the sensitive probe, it cannot be used to take measurements while the laser is on. The drawback of this technique is that the measurements need to be taken as soon as possible (in a matter of a few milliseconds) after the laser has been turned off. Also, the number of cycles of alternate on and off laser will help to find accurate and precise values. Harry Slatyer, a PhD student, has mentioned in a statement that his team analyzed the cooling effect really well and with clever data processing they can possibly ameliorate the sensitivity and can even put an end to the need for a cooling laser.
To know more about the research you can have a look at the research paper titled #-Link-Snipped-# which was published in Journal Nature Communications.
Source: #-Link-Snipped-#
According to Ping Koy Lam, from the Research School of Physics and Engineering at ANU, the atomic force microscopes are extraordinarily sensitive while measuring the microscopic objects but the probe of the microscope which is 500 times finer as compared to human hair is often prone to vibration at room temperature. The vibrations are caused when the probe becomes warm. Moreover, these vibrations can distort the measurements. With a perspective of stopping the motion while taking measurements and improve the measuring capability of the microscope, the laser physicists of Quantum Optics Group focused lasers at the probe. They have tried to control the warping effect (effect related to distortion caused by thermal vibration of the probe).
As the laser affects the sensitive probe, it cannot be used to take measurements while the laser is on. The drawback of this technique is that the measurements need to be taken as soon as possible (in a matter of a few milliseconds) after the laser has been turned off. Also, the number of cycles of alternate on and off laser will help to find accurate and precise values. Harry Slatyer, a PhD student, has mentioned in a statement that his team analyzed the cooling effect really well and with clever data processing they can possibly ameliorate the sensitivity and can even put an end to the need for a cooling laser.
To know more about the research you can have a look at the research paper titled #-Link-Snipped-# which was published in Journal Nature Communications.
Source: #-Link-Snipped-#