Many critical cellular functions rely on the cells' ability to adhere to each other. But just how sticky are they? We now have microscopes that can see single molecules, but wouldn’t it be better to be able to directly feel them? Well, we can't quite fondle individual molecules with our finger tips, but Cécile Pacoretand Stéphane Régnier of the Université Pierre et Marie Curie have tested and improved ‘haptic optical tweezers' that let us come pretty darn close.
These instruments use highly focused lasers to produce a localized 3D electromagnetic field that holds a tiny tool in place. The microtools are steered by shifting or defocusing the laser. A robot translates the picoNewton forces of atomic scale particles into the range at which the operator can feel. For the first time, researchers were able to ‘feel’ properties like cell adhesion.
Conceptual representation of a highly nimble micromanipulation experimental setup. Cells can be explored with advanced laser trapped microtools that extend the operator's sense of touch thanks to a specifically designed haptic teleoperated optical tweezers. Credit: Pacore/UPMC.
Pacoret C, & Régnier S (2013). Invited Article: A review of haptic optical tweezers for an interactive microworld exploration. The Review of scientific instruments, 84 (8) PMID: 24007046.