Prof. Mervyn Miles
Centre for Nanoscience & Quantum Information
University of Bristol, UK
Mervyn Miles is Professor of Physics and Director of the Centre for Nanoscience & Quantum Information at the University of Bristol. His research activity in the last 25 years has focused on the development and application of new scanning probe microscopes with specific applications in soft matter. Recent successes include the invention of two new types of high-speed atomic force microscopes (AFM). Another research area, is the use of nano and micro tools controlled by holographic optical tweezers to manipulate cells and to act as a new type of AFM probe.
Mervyn is a co founder of two spin-out companies Nu Nano and Infinitesima, working in the fields of novel AFM probes and high-speed AFM for the semiconductor industry, respectively.
Positions and Employment
- Professor of Physics, University of Bristol, UK
- Director of the Centre for Nanoscience & Quantum Information, the University of Bristol, UK
Other Experience and Professional Memberships
- Co founder of Nu Nano and Infinitesima
- Fellow of the Royal Society
- CPhys - Chartered Physicist, Institute of Physics, London, UK
- Royal Society Wolfson Research Merit Award Holder
High-speed non-contact AFM to Holograph optical 4π AFM
Mervyn Miles (1), R. Harniman (1), D.J. Phillips (1), L.M. Picco (1), O. Payton (1), M. Antognozzi (1), S. Simpson (1), S. Hanna (1), D.J. Engledew (1), G. Gibson (2), R. Bowman (2), M.J. Padgett (2)
(1) Nanoscience & Quantum Information Centre, University of Bristol, U.K. & (2) School of Physics and Astronomy, University of Glasgow, U.K.
AFM is complementary to many other microscopies, and offers many benefits such has high-resolution 3D imaging in many environments including liquids. However, there are three areas in which conventional AFM has limitations: (i) a low imaging rate, (ii) the probe-sample force interaction, and (iii) the planar nature of the sample. We are develop-ing two high-speed force microscopy techniques to overcome the first two of these, (i) and (ii).
(i) One high-speed AFM (HS AFM) technique is a DC mode in which an automatic feedback mechanism essentially arising from the hydrodynamics of the situation maintains a tip-specimen separation of about 1 nm. This technique routinely allows video-rate imaging (30 frames per second, fps) and has achieved imaging at over 1000 fps, i.e., 100,000 times faster than conventional AFM. Damage to specimens resulting from this high-speed DC-mode imaging is surprisingly less than would be caused at normal speeds. The behaviour of the cantilever and tip at these high velocities has been investigated and superlubricity is a key component in the success of this technique [1,2].
(ii) The other high-speed force microscope is a non-contact method based on shear-force microscopy (ShFM). In this HS ShFM, a vertically-oriented, laterally-oscillating probe detects the sample surface at about 1 nm from it as a result of the change in the mechanical properties of the water confined between the probe tip and the sample. With this technique, very low normal forces are applied to the specimen. There is a bonus of obtaining information on the structure of the molecular water layers as a function of position over the sample surface[3,4].
(iii) AFMs require planar samples because the probe scans in a plane. It is as if the tip is only ‘seeing’ the sample from above. We have overcome this limitation by steering the tip of a nanorod in a three dimensional scan with six degrees of freedom using holographically generated traps such that it is possible to scan around a sample from any direction. Various probe types have been utilized, including silica nanorods, rod-like diatoms, and custom designed, two-photon polymerized 3D structures [5,6].
1. Payton, OD, et al., Nanotechnology 23 (2012) Art. No. 265702.
2. Kalpetek, P, et al., Measurement Sci. & Technol., 24 (2013) Art. No. 025006.
3. Harniman RL, et al., Nanotechnology 23 (2012) Art. No. 085703.
4. Fletcher, J, et al., Science 340 (2013) online April 11th.
5. Phillips DB, et al., Nanotechnology 22 (2011) Art. No. 285503.
6. Olof SN et al., Nano Letters 12 (2012) 6018-6023.