Welcome
Read the recent Boston Globe article on the Surface Metrology Lab.
Surface Metrology is the study of surface geometry, also called surface texture or surface roughness. The approach is to measure and analyze the surface texture in order to be able to understand how the texture is influenced by its history, (e.g., manufacture, wear, fracture) and how it influences its behavior (e.g., adhesion, gloss, friction).
Quantitatively the objective in surface metrology is to be able to use texture measurements and analysis to differentiate and correlate surfaces with different behavior or histories. These differentiations and correlations support product and process design, quality assurance, in engineering. Surface metrology can also be used to support scientific discoveries in a variety of fields including anthropology, archeology, geography, geology, and biochemistry.
Upcoming Seminars:
October 29-30, 2007
The scale of interest in surface metrology depends on the application, and is generally in the nanometer to micrometer range. Usually the scale of interest is just below the scale of the form, e.g., the curvature in a bearing. In geography this form could be as large as tens of kilometers. As nanotechnology drives the scales of designed, regular forms, to nanometer scales, surface metrology is used to study these fine scale forms as well.
Background
WPI's Surface Metrology Laboratory was founded in 1990 by Professor Christopher Brown who has more than twenty-five years of experience working in surface metrology in the US and Europe. It is the only academic laboratory in the US dedicated to advancing the understanding of the formation, behavior, measurement and analysis of surface roughness.
The lab has been a significant source of innovations and discovery and it enjoys a worldwide reputation for contributing to breakthroughs in the understanding of the role of surface roughness in adhesion and friction. Brown and the lab's associate director, Toby Bergstrom, are members of ASME B-46 committee on surface textures and develop national and international standards for surface metrology.
The lab has pioneered technological development and industrial applications of scale-sensitive fractal analyses, a method invented and patented by Prof. Brown and co-workers. The lab has studied a broad range of surfaces including hard drives, cutting tools, skin, teeth, food, rocks, skis, pills, pavements, tires, bullets, and industrial diamonds. The lab has developed advanced techniques for differentiating surfaces based on texture measurements and for finding the scales at which the differentiation can be made.
Graduate and undergraduates typically work together on a variety of projects. Recent projects include characterizing scratches on teeth supported by the NSF, surface of pill compacts supported by Pfizer, fractography of chocolate, and the structure of ground ski bases. Current projects include the measurement of paper, granite and grinding wheels, and the determination of uncertainty, and noise control and management in surface measurements.
Philosophy
The challenges facing industry in the field of surface metrology can best be met through collaborative efforts with academic researchers. The partnership between the WPI Surface Metrology Laboratory and industry promotes a collaboration, where academic researchers and industrial practitioners can share and test ideas through research in both environments. The Surf Met Lab's objective will be met through the successful utilization of industrial and academic resources.
Experience
Over the past ten years we have had many interesting applications and collaborations with labs in the US, Canada, Europe and Chile. Frequently Surf Met Lab supports the surface measurement and analysis, while the collaborators make experimental measurements in their labs.
- Wear and friction on pavements are not coupled (Dr. W.A.Johnsen, WPI MS'95, PhD'98).
- Friction measurements and pavement texture are correlated using area-scale fractal analysis, neural networks, and measurements from the lab's scanning laser microscope (SLM) at the NASA Wallops Flight Facility (Dr. Johnsen built the SLM at WPI).
- Adhesive strengths in thermal spray systems were correlated with substrate texture using area-scale fractal analysis -- supporting a general, scale-based model of adhesion and substrate surface texture (with Dr. Stephan Siegman, EMPA -- Thun, Switzerland).
- Electrochemical impedance spectra on zirconia were correlated with surface measurements by atomic force microscopy using area-scale analysis (with Dr. Glen McRae, Chalk River Labs, Ontario, Canada).
- Hard disks stop-start friction with sliders has been correlated with disk texture measurements made with an atomic force microscope (with Prof. Francis Kennedy, WPI BS'63 and his students at Thayer School of Engineering, Dartmouth College).
- Skin treatments have been correlated with texture measurements made with a skinvisometer by Dr. Konstantin Ariticus of proDERM, Hamburg, Germany.
- Food textures have been measured with Surf Met Lab's scanning laser microscope and analyzed using area-scale fractal analysis by visiting scientist Franco Pedreschi of the Pontificia Universidad Cathólica de Chile, Santiago.
- Fracture surfaces measured with a confocal microscope at NASA Lewis Research Labs and with the lab's scanning laser microscope (with Prof. Isa Bar-on of WPI).
- Other surfaces analyzed include: tires, bearings, ski bases, bowling balls, bone substitute, potato chips, contact lenses, teeth, shell casings, bullets, and paper.
Through conferences and invitational lectures, short courses and collaborations with visiting scholars, results of our work have been presented in over a dozen countries on four continents.
If you have any questions regarding the laboratory facilities, staff, or lab work, please do not hesitate to contact us at surface@wpi.edu
Maintained by webmaster@wpi.eduLast modified: October 22, 2007 10:58:15