Optical Tweezers

Optical tweezers are a really cool technique, and actually surprisingly easy to make for something that was only discovered in the 70s.

In my 3rd year undergraduate optics lab we were given a laser, a camera, and a bunch of mirrors and lenses and told to make an optical tweezer and take measurements on the trapping potential for a bunch of different sized polystyrene beads. It was challenging, but ultimately quite do-able for a couple of undergrads with minimal advice / assistance from the lab coordinators.

If I ever had any doubt about whether or not I wanted to be an experimental physicist though, that lab really did confirm to me that I'd hate being an experimentalist. Give me a whiteboard any day.

For those interested, here is Arthur Ashkin giving what would have been his 2018 Nobel Lecture in Aspen, Colorado, in early 2019. He was unable to travel to Stockholm at the time. The talk is quite accessible if you want to understand how tweezers work.

https://youtu.be/vb58pd2ycKQ

If curious see also

2018 https://news.ycombinator.com/item?id=18120496

My favorite demo of optical tweezers in action is the tetris video: https://youtu.be/paSWFnfv1n4

How's that for a lab trick!

Wow, never thought I'd see optical tweezers on HN. Flashbacks of rheology / microrheology are crossing my mind ...

I wonder if the science at work here could lead to the creation of a tractor beam capable of moving larger objects.