Noncontact dielectric friction.
Dielectric fluctuations are shown to be the dominant source of noncontact friction in high-sensitivity scanning probe microscopy of dielectric materials. Recent measurements have directly determined the friction acting on custom-fabricated single-crystal silicon cantilevers whose capacitively charged tips are located 3-200 nm above thin films of poly(methyl methacrylate), poly(vinyl acetate), and polystyrene. Differences in measured friction among these polymers are explained here by relating electric field fluctuations at the cantilever tip to dielectric relaxation of the polymer.
Kuehn
Seppe
S
Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.
Marohn
John A
JA
Loring
Roger F
RF
D017097:Electric Impedance; D017276:Friction; D008422:Materials Testing / Q000379:methods*; D020527:Microscopy, Scanning Probe / Q000295:instrumentation / Q000379:methods; D008956:Models, Chemical; D055095:Optics and Photonics; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry; D012828:Silicones / Q000737:chemistry; D013499:Surface Properties
D011137:Polystyrenes; D011145:Polyvinyls; D012828:Silicones; C013215:polyvinyl acetate; D019904:Polymethyl Methacrylate