Ultrasonic particle manipulation and their application across the length scales
Professor Bruce Drinkwater, University of Bristol
Abstract:
Ultrasonic particle manipulation can be thought of as non-contacting robotic hands capable of moving and assembly objects. It is applicable across a very wide range of length scales from the micrometre level required for objects such as cells to the macroscopic scale required to manipulate small components. It is an enabling technology – not only can it improve and complement existing manipulation technologies, but it also enables completely new manipulation and manufacturing applications. Lab-on-a-chip devices can be used to sort red blood cells from fat particles. Larger devices can be used to hold millimetre-scale samples in place for crystallographic analysis. Successful manipulation is achieved by creating a convergent force field on the object using an array of ultrasonic sources. Examples will be shown in which high performance devices can be manufactured at relatively low cost using readily available components. Current and future applications across engineering and biomedicine will be discussed.
Bio:
I was born in Hexham, England, in 1970. I received B.Eng. and Ph.D. degrees in Mechanical Engineering from Imperial College, London, England, in 1991 and 1995 respectively. My Ph.D. thesis was on improved ultrasonic devices for crack and corrosion detection in engineering structures. Since 1996, I have worked as an academic in the Mechanical Engineering Department at the University of Bristol. Between 2000 and 2005 I was an EPSRC Research Fellow and in 2007 I was promoted and given the title Professor of Ultrasonics. I now have the privilege of leading an incredibly enthusiastic research group working on ultrasonics and non-destructive testing. My research interests span pretty much anything with any connection to ultrasonics. But to-date I have published more than 100 journal articles covering…
1) Ultrasonic measurement of adhesive joints, thin layers, and interfaces. Despite bring small, these are often the weak link in critical machines such as the turbines in power stations.
2) Ultrasonic array imaging for the assessment of engineering structures. This allows small defects such as cracks to be more accurately detected and characterised.
3) Acoustic radiation force devices for large-scale and small-scale particle manipulation applications. This includes such things as acoustic levitation and tractor beams.
My research on ultrasonic imaging has led to the successful commercialisation of an array wheel probe which is now widely used to check that aircraft are safe to fly. In 2010 I received the Roy Sharpe Prize for this work. The imaging techniques I helped develop (known in the trade as Full Matrix Capture and the Total Focusing Method) are now widely used in the engineering industry. In 2016 I received the UK nomination for the Sokolov research award as well as the Vice Chancellor’s Impact Award. In 2017 I received a Royal Society Wolfson Research Merit Award. These awards recognise the benefits to industry and society of my research.
In 2015 I co-invented the world’s first stable ultrasonic tractor beam which was widely featured in the popular press. In 2017 the levitation of wavelength-scale objects also receive significant press attention. Potential applications of this technology are diverse and I am now working on using these ideas for ultrasonically assisted 3D printing and the assembly of living tissue.
I am a passionate advocate of the importance of engineering and science to society, be it by improving our living standards or, alongside the arts, worthy of being pursued for its own sake. This has led to two appearances on the science slot in BBC One’s The One Show as well as an interviews on Radio 4’s PM news programme and Inside Science. I have exhibited my research at the Cheltenham Science Festival twice and the Royal Society Summer Science Exhibition three times. Have a look at this video I made with the Royal Society as part of the Brian Cox Schools Experiments series. In 2016 I was privileged to be asked to speak at a Star Trek film screening on tractor beams, thereby bringing together science fact and science fiction.