Nanosprings

University of Idaho - Moscow ID
Mar 2012-Current
- Research Assistant

Nanosprings

Nanospring
A nanowire wrapped into a helix. [1]
Nanowire
A nanowire is a nanostructure, with the diameter of the order of a nanometer (10−9 meters). This term may be used to describe wires that have a diameter in the tens of nanometers.[2]
A.L.D.
Atomic layer deposition (ALD) is a thin film deposition technique that is based on the sequential use of a gas phase chemical process. [3]

Nanosprings form via a modified vapor-liquid-solid (VLS) mechanism. Essentially, a liquid metal droplet (catalyst) absorbs material from the vapor. For example, in the case of boron carbide nanosprings boron and carbon introduced in vapor form is absorbed by either a NiB or FeB droplet. Once the concentration of the building block material reaches supersaturation the excess material is expelled from the base of the catalyst where it solidifies into a nanowire. The modified VLS mechanism that is responsible for nanospring formation is referred to as contact angle anisotropy (CAA). CAA produces assymetric growth rates about the catalyst thereby driving the catalyst at the end of the nanowire to follow a helical trajectory. The diameter of the nanowire forming the nanospring is approximately 20 nm, the pitch of the spring is approximately 25nm and the diameter of the nanospring is 60 nm.

Nanosprings come in a variety of flavor including boron carbide, silicon carbide and silicon dioxide. However, nanosprings can be formed from any material as long as nanowires of that material can grow by VLS.

Our research focuses on the controlled growth of nanosprings, measurement of their mechanical properties, and the development of nanospring devices. We are happy to acknowledge the generous support of this project on thepart of the W. M. Keck Foundation.

—David N. McIlroy, Ph.D, University of Idaho [4]


Utilizing Atomic Layering Deposition techniques, explore various methods and materials for coating of existing Nanosprings.

Actions to date:

  • Rewire cable for Mass-Flow Controller
  • Build Customized enclosure for powersupply with variable voltage output and signal output testing posts
  • Calibrate Voltage selector
  • Measure flow in mL/sec Vs voltage
  • Replace temperature control module on furnace
  • Construct frame for Atomic Layer Deposition system
  • Assemble manifold, pumps, gates, and switches for A.L.D system
  • Customize Labview program for A.L.D cycle
  • Cut and clean wafers in preperation for Nanospring growth
  • Coat Wafer with gold using chemical vapor deposition
  • Grow Nanosprings
  • Coat Nanosprings with various compounds via A.L.D

Pictures and Images