Hybrid optical and acoustic trapping

The need for non-contact micromanipulation methods is apparent for a number<br/>of different applications. Optical tweezers, a technique which uses highly focused laser beams to trap and move microscopic objects, has become an important tool for many applications owing to its incredible precision and dexterity. Optical trapping is, however, limited in several ways. It often struggles with particles larger than 10 micrometers, agglomerates and large numbers of particles.<br/><br/>Complimentary technologies such as acoustic trapping, aim to overcome some<br/>of these limitations. This technique, also termed as Sonotweezers, uses ultrasonic fields to manipulate particles and can manipulate large particles with ease and manipulate large numbers of polydisperse particles and agglomerations, although they currently lack the dexterity of optical tweezers. Combining these two trapping modalities overcomes the some of the limitations of both of them and opens up a new range of useful applications.<br/><br/>Three main types of hybrid optical and acoustic traps have been devised and<br/>are presented here. The first is an acoustic Bessel beam trap which is used to<br/>arrange a large number of polydisperse particles into concentric rings whereupon the smaller particles can then be further manipulated using a single beam optical tweezer.<br/><br/>A rudimentary optical sorting system, which pushes particles in a flow laterally using an optical trap, has been combined with an acoustic levitator, which moves all particles away from the edges of the microfluidic channel reducing on sticking and other negative effects.<br/><br/>A novel optically transparent ultrasonic device has been developed for easier integration into optical traps without the need for modication. This transparent trap has also been used in combination with a multibeam interference optical<br/>sorter to improve the separation between 5 and 10 micron particles.

Name dc:type.qualificationname

Doctor of Philosophy

Level dc:type.qualificationlevel

Doctoral Thesis

Grantor dc:publisher.institution

University of Dundee

Year dc:date.issued

2014

Author dc:creator

• Brodie, Graham

Advisor dc:contributor.advisor

• MacDonald, Michael

• Optical
• Acoustic
• Trapping
• Tweezers
• Ultrasound
• Sorting
• Hybrid
• Sonotweezers
• Transparent
• Bessel

Language dc:language

eng

Identifier

oai:discovery.dundee.ac.uk:studenttheses/8c6f10f1-7e43-4336-8e10-4d146ae87785

OAI identifier oai:identifier

oai:discovery.dundee.ac.uk:studenttheses/8c6f10f1-7e43-4336-8e10-4d146ae87785