COLL 110 |
| Alistair P D Elfick1, Jasmin Zhao1, Anthony Unsworth2, Kevin E. Healy3, and Lisa A. Pruitt4. (1) Department of Mechanical Engineering, University of California Bekeley, 2121 Etcheverry Hall, Berkeley, CA 94720, (2) Centre for Biomedical Engineering, University of Durham, School of Engineering, South Road, Durham, DH1 3LE, United Kingdom, (3) Departments of Bioengineering and Materials Science and Engineering, University of California, 465 Evans Hall #1762, Berkeley, CA 94720-1762, (4) Department of Bioengineering and Mechanical Engineering, U.C. Berkeley, 5134 Etcheverry Hall, U.C. Berkeley, Berkeley, CA 94720 |
| Understanding the role of proteins in mediating adhesion force and friction for bioMEMs devices is fundamental to their success. This study investigates the nanotribological properties of two proteins adsorbed to model ultraflat SiO2 surfaces. LFM using a borosilicate microsphere tipped cantilever of radius 10.9µm was used to maintain ‘low’ contact stresses (DI Bioscope IIIa). A range of tribological variables were studied; three lubricants (PBS, PBS + 1mg/ml BSA, PBS + 10mg/ml IgG, all where pH 7.4 @ 25°C), normal load 2-40nN and sliding velocity 1, 5 or 10 µm/s. Quartz crystal microbalance with dissipation monitoring (QCMD, Q-Sense) was used to establish the biomolecular adsorption dynamics. Protein adsorption was confirmed to be rapid and irreversible. The co-efficient of friction was found to increase approximately 40% in the presence of adsorbed protein. This contrasts to previous LFM work showing no significant modification in friction for contact stresses two orders of magnitude greater. |
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Friction, Lubrication, and Adhesion in Micro- and Nano-Scale Devices
8:30 AM-12:00 PM, Monday, March 29, 2004 Marriott -- Orange County 5, Oral
Division of Colloid and Surface Chemistry |