Prof. Steven L. Neale
The University of Glasgow, Scotland, UK
Title: Size-scaling effects for microparticles and cells manipulated by optoelectronic, optical and acoustic tweezers
Abstract:
It is possible to move and manipulate microscopic particles with touch-free forces by passing momentum from an incident wave to the particle. The most well know demonstration of this is in Optical Tweezers, for which Arthur Ashkin won the Nobel prize in 2018. Here momentum is passed directly from light rays to the particle when the light is absorbed, scattered, reflected or refracted. In this talk we will focus on a technique which is complimentary to Optical Tweezing, called Optoelectronic Tweezing (OET), which relies on light patterned electrical fields to induce dielectrophoresis forces in the particle. We will see how OET can extend the size and number of particles that can be manipulated in parallel and discuss its relative advantages and disadvantages. Finally, we will consider acoustic tweezing, comparing and contrasting the manipulation it allows with respect to both Optical and Optoelectronic Tweezing; showing it is Optical Tweezing that allows the finest measurement of forces, OET that allows the control of the largest number of particles whilst retaining individual particle control and acoustic tweezing that offers a route to manipulate larger particles in air.
Biography:
Steven L. Neale is Professor of Micro Engineering and Head of the Systems, Power and Energy Research Division in the James Watt School of Engineering at the University of Glasgow. He joined the University of Glasgow in 2009 with a Royal Academy of Engineering Research Fellowship in Biomedical Engineering after spending two years at UC Berkeley studying Optoelectronic Tweezers with Prof Ming C. Wu. Prior to this Prof Neale had studied at the University of St Andrews taking an MSci in Physics 1998-2002 and PhD in Optically Controlled Microfluidics 2002-2006 under the supervision of Prof Thomas Krauss’s and Prof Kishan Dholakia. Prof Neale is a Fellow of the Institute of Physics, FInstP.
Prof Neale’s research interests lie in two areas: first, the micro-manipulation of particles in suspension for industrial and medical applications and second the development of micro fabricated biomedical devices for medical diagnostics and therapies. Specifically, he has expertise in the micro fabrication of electrodes as impedance-based biosensors and the manipulation of micro particles with optical, electrical and acoustic forces. Prof Neale’s most significant contributions to the field have been in the area of extending the range of particles that can be manipulated with optical patterned electrical forces in an Optoelectronic Tweezers (OET) device. This work, which has shown the manipulation of particles from around 1nm to almost 1mm in size, demonstrates the versatility of this “touch free” control mechanism which he intends to keep exploring for utilisation in manufacturing.