AVS 51st International Symposium
    Nanometer-scale Science and Technology Thursday Sessions
       Session NS2-ThA

Paper NS2-ThA10
Devices Formed Using Deposited Polymeric Nanofibers

Thursday, November 18, 2004, 5:00 pm, Room 213D

Session: Nanowires II
Presenter: H.G. Craighead, Cornell University
Authors: J. Kameoka, Cornell University
H. Liu, Cornell Univeristy
D. Czaplewski, Cornell University
R. Mathers, Cornell University
S. Verbridge, Cornell University
G. Coates, Cornell University
H.G. Craighead, Cornell University
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We have used deposited polymer nanofibers for the formation of electrical, optical and mechanical devices. We used a microfabricated tip as a controlled scanning source for electrostatically driven deposition of oriented nanofibers and for interfacing the fibers to lithographically defined surface structures. Because of the ability to deposit these materials as individual oriented fibers with diameters in the range of 50 nm to ~1µ, they can be utilized in new device architectures. In this talk we describe the use of the deposited polymer nanofibers as chemical sensors and as templates for the formation of mechanical and nanofluidic devices composed of inorganic materials. Utilizing the properties of a conducting polyaniline polymer we have formed ammonia sensors comprising a single oriented fiber deposited on gold electrodes. We created mechanical devices such as silicon nitride mechanical oscillators with dimensions on the order of 100 nm, formed using deposited poly(methylmethacrylate) fibers. The oscillators were defined in a silicon nitride layer by using the fiber as a mask for reactive ion etching, followed by removal of a sacrificial underlying layer. After releasing the devices, the frequencies of the modes of oscillation of the beams were determined by laser interference techniques. We fabricated nanofluidic channels of elliptical cross-section, without the use of high resolution lithography. The sacrificial template fiber consisted of a heat-decomposable polycarbonate that was deposited on a substrate and encapsulated by a spin-on glass. The channels were formed by thermal removal of the sacrificial polymer nanofibers. The oriented nanofiber deposition method, used in these experiments, offers an approach for the rapid formation of self-assembled nanoscale devices, connected to microfabricated structures, which would be difficult to form using a completely self-assembled or completely lithographic approach.