Nanowire sensor and actuator
Date
2006
Authors
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Publisher
University of Delaware
Abstract
Nanowires and nanotubes are a new class of quasi one-dimensional materials that have been attracting great research interest in the last few years. Their superior electrical, mechanical, optical and thermal properties permit them to be used as fundamental building blocks for nanoscale science and technology in fields ranging from electronics, photonics, and robotics to chemical and biological sensors. The present work reports the growth of single-wall carbon nanotubes by the thermal CVD of methane on silicon wafers. These nanotubes were then used as templates for the fabrication of metallic nanowires of silver and platinum by electrochemical deposition. Platinum nanowires were then applied in the field of actuators and sensors as an electrochemical actuator and a chemical sensor. The fabrication of platinum nanowire sheets allowed the use of nanowires as the main actuating element while the deposition of the nanowires on top of microhotplates, micro-machined in-house using silicon, allowed the testing of their sensitivity to various chemical gases at elevated temperatures. The platinum nanowire actuator recorded strain values higher than those achieved by current commercial actuators, such as piezoelectric materials, at extremely low voltages. When used as a chemical sensor, the nanowires were found to be more sensitive than other recently reported metallic nanowire sensors, recording more than 160% change in resistance.