Physics Colloquium
Materials at the nanoscale: from nanowires to biological cells
3:30 pm
Jorgensen Hall Room: 136
Abstract:
Nanoscale materials enable new phenomena to be investigated and new properties to be measured. Our group has developed a method for fabricating metallic nanowires that are being used to attain both of these goals. The single crystalline nanowires that we grow may be composed of a variety of different metals and grown between specified points in existing circuitry or, say, from the tip of a tungsten electrodes. We have recently achieved the growth of 60 nm diameter nanowires with lengths in excess of 100 ?m (aspect ratio > 103). Such long branchless nanowires are needed for future studies of ultrafast electronic excitations in the wires under strong electric fields. Independently, we have applied these nanostructures to the investigation of adhesion by living biological cells. It has been essential in this study to fabricate instruments that are small enough to be interfaced with localized sites on individual cells. This capability has allowed us to determine the fundamental adhesive properties of the amoeboid cell D. discoideum. These properties include the cell-substrate adhesion energy, the bending modulus of the cellular membrane, and the interfacial tension of the membrane-medium interface. Our nanowire fabrication method and new results from both of these efforts will be discussed in this talk.
Nanoscale materials enable new phenomena to be investigated and new properties to be measured. Our group has developed a method for fabricating metallic nanowires that are being used to attain both of these goals. The single crystalline nanowires that we grow may be composed of a variety of different metals and grown between specified points in existing circuitry or, say, from the tip of a tungsten electrodes. We have recently achieved the growth of 60 nm diameter nanowires with lengths in excess of 100 ?m (aspect ratio > 103). Such long branchless nanowires are needed for future studies of ultrafast electronic excitations in the wires under strong electric fields. Independently, we have applied these nanostructures to the investigation of adhesion by living biological cells. It has been essential in this study to fabricate instruments that are small enough to be interfaced with localized sites on individual cells. This capability has allowed us to determine the fundamental adhesive properties of the amoeboid cell D. discoideum. These properties include the cell-substrate adhesion energy, the bending modulus of the cellular membrane, and the interfacial tension of the membrane-medium interface. Our nanowire fabrication method and new results from both of these efforts will be discussed in this talk.