Nanowerk  September 8, 2023
Optical tweezers are used from manufacturing to biotechnology. However, the requirement of refractive index contrast and high laser power results in potential photon and thermal damage to the trapped objects. Optothermal tweezers have been developed to trap particles and biological cells via opto-thermophoresis with much lower laser powers. But the intense laser heating and stringent requirement of the solution environment prevent their use for general biological applications. A team of researchers in the US (UT Austin, UT Dallas) has proposed hypothermal opto-thermophoretic tweezers (HOTTs) to achieve low-power trapping of diverse colloids and biological cells in their native fluids. The tweezers exploit an environmental cooling strategy to simultaneously enhance the thermophoretic trapping force at sub-ambient temperatures and suppress the thermal damage to target objects. They applied HOTTs to the three-dimensional manipulation of functional plasmonic vesicles for controlled cargo delivery. According to the researchers the noninvasiveness and versatile capabilities of HOTTs is a promising tool for fundamental studies and practical applications in materials science and biotechnology… read more. Open Access TECHNICAL ARTICLEÂ
Working principles of HOTTs. Credit: Nature Communications volume 14, Article number: 5133 (2023)Â