Tuesday, 14 October 2014

SPIE Conference Proceedings: OTOM XI

Proceedings from the SPIE Optics + Photonics 2014 conference have been published.  These include Chris F's paper on optical and acoustic manipulation of microbubbles in a microfluidic device: C. R. Fury, P. H. Jones and G. Memoli.  'Multi-scale manipulation of microbubbles employing simultaneous optical and acoustical trapping', Proc SPIE 9164, Optical Trapping and Optical Micromanipulation XI, 91642Z, doi: 10.1117/12.2061622 (2014).

From the abstract: We present a dual-modality microbubble trapping system that incorporates the fine spatial resolution of optical tweezers, with the long range, high force manipulation of acoustic tweezers, in a single microfluidic system. We demonstrate aggregation of polymer microbubbles in the node of an acoustic field, and subsequent selection and separation of a single microbubble using holographic optical tweezers. We further characterize the optical tweezers by measuring the transverse spring constant, and use the calibrated trap to determine the acoustic force on the bubble for varying parameters of optical trap diameter and power, and acoustic frequency and driving voltage. Further development of the system to include acoustic emission measurement is presented, with the goal of having a multi-purpose mechanical and cavitation detection set-up combined into a single system

Monday, 13 October 2014

New Group Members

Two new members have joined the Optical Tweezers Group at the start of the 2014-15 academic year.  Nick Tidy has joined us as a PhD student.  Nick studied Physics at Birmingham University and graduated in 2014.  He will be working with our collaborators at JAIST on optical trapping of polymer vesicles.  Stefan Siwiak-Jaszek is a fourth year undergraduate at UCL studying Natural Sciences.  Stefan spent the third year of his degree studying at the National University of Singapore, and has retured to UCL for his final year where he will be using optical tweezers to study stochastic thermodynamic processes for his MSci project.