Since the invention by Arthur Ashkin in 1986, the optical tweezers have been an important tool for physics and biology. These optical tweezers can trap micro/nanoparticles without any physical contact while simultaneously measuring pN-level forces and nm displacements. However, traditional optical tweezers based on objective lenses have been limited within research labs, due to the expensive and bulky setup and susceptibility to environmental fluctuations. In this talk, I will discuss the recent progress on fiber-based optical tweezers, with an aim of bringing this technology out of the labs. Our fiber optical tweezers are small (~ 1x1x0.5 in^3), modular, and portable, while maintaining the capabilities of both microparticle trapping and nm-resolution displacement measurements. I will focus on a unique application of the modular fiber tweezers in disease diagnosis by single cell stiffness interrogation. Other potential applications including brain tissue mechanical measurements and trapping in air will also be discussed.

Yuxiang (Shawn) Liu is an associate professor in Mechanical Engineering, who joined WPI in 2013. He received a Ph.D. in Mechanical Engineering from University of Maryland, College Park in 2011. Before joining WPI, Yuxiang Liu worked at National Institute of Standards and Technology (NIST) as a NIST-ARRA fellow from 2011 to 2013. His research interests include fiber based optical trapping, fiber optical sensors, silicon nanomechanics and nanophotonics, optofluidics, and cell mechanics.