1. Biomedical Applications of Scanning Probe Microscopy
Dr James R Smith
School of Pharmacy and Biomedical Science
University of Portsmouth

2. Content What is Scanning Probe Microscopy (SPM) ? Principles of SPM
How does it differ from SEM/TEM ?
SPM Facilities at Portsmouth
Selected Case Studies
Summary
Questions

3. What is SPM ? SPM is a revolutionary technique which allows:
3-D imaging
nanometre or micrometre scale
imaging in a variety of environments
with minimal sample preparation

4. SPM Techniques
SPM is a generic name for a number of related ‘probe’ techniques:
Scanning Tunnelling Microscopy (STM)
Atomic Force Microscopy (AFM)
others, such as Scanning Thermal Microscopy (SThM), Scanning Electrochemical Microscopy (SECM), Magnetic Force Microscopy (MFM)

5. Historical Background
Scanning Tunnelling Microscopy (STM) was first reported in 1982 by Binnig et al.
Atomic Force Microscope (AFM) first appeared in 1986
Commercial SPM instruments capable of STM and AFM operation available in 1992

6. Principles of AFM

7. Advantages of SPM over TEM and SEM
Nanometre/atomic resolution
Accurate height measurements to within 1 angstrom
Three-dimensional representation of images
Does not require UHV
Ability to perform studies in aqueous environments
Manipulation of surfaces on sub-nanometre scale

8. Other Information from SPM
Surface roughness
Surface area
Hardness/softness
Elasticity
Adhesion
Friction

9. Nanoindentation of Bacterial Cells

10. SPM Facilities at Portsmouth
TopoMetrix Discoverer TMX2000 Modular SPM

11. Biomedical Applications of SPM at Portsmouth
Surface metrication of hip prostheses
Contact lens manufacture and fouling
Hair structure and disease
Biocide action
Polymer binding to human cells
Surface roughness of skin
RNA/DNA secondary structure
anti-cancer drug design

12. Biodeterioration and Control
Biofilm contamination on an intraocular lens
Action of a biocide on E. coli

13. Surface Metrication of Hip Prostheses

14. Soft Contact Lens Manufacture
Polypropylene injection mould
Pigment distribution on a tinted soft contact lens (above) and surface roughness (left)

15. Human Hair Surface roughness/line profile A=‘A’-layer, B=exocuticle,
C=endocuticle (above)
Same hair sample imaged under water
showing swelling (right)

16. Summary Nanometre/atomic resolution
Accurate height measurements to within 1 angstrom
Three-dimensional representation of images
Does not require UHV
Ability to perform studies in aqueous environments
Minimal sample preparation
Minimal damage to sample
Manipulation of surfaces on sub-nanometre scale

17. Acknowledgements Staff and students at Portsmouth
Dr S A Campbell - Portsmouth
Prof F C Walsh - Portsmouth
Dr B F Shahgaldi - St Thomas’ Hospital, London
Dr J A Swift - Unilever/De Montfort University
Dr A Gough - Alberto-Culver Company (UK) Ltd
Dr D H Morton - Clinic For Special Children, Philadelphia
Staff and students at Portsmouth