What is Smart Dust?
- A dust mote is an autonomous node incorporating sensing, computing, communications and a power source in a mm3 volume.
- A colletion of dust motes is dispersed troughout an environment.
- Dust motes use wireless communication to relay information to a base station over distances of 10s to 1000s of meters.
Applications of Smart Dust
- Civilian Surveillance
Micrometer-sized one-dimensional photonic crystals of porous Si that spontaneously assemble, orient, and sense their local environment are prepared. The photonic crystals are generated by electrochemically etching two discrete porous multilayered dielectric mirrors into Si, one on top of the other. The first mirror is chemically modified by hydrosilylation with dodecene before the etching of the second mirror, which is prepared with an optical reflectivity spectrum that is distinct from the first. The entire film is removed from the substrate, and the second mirror is then selectively modified by mild thermal oxidation. The films are subsequently fractured into small particles by sonication. The chemically asymmetric particles spontaneously align at an organic liquid–water interface, with the hydrophobic side oriented toward the organic phase and the hydrophilic side toward the water. Sensing is accomplished when liquid at the interface infuses into the porous mirrors, inducing predictable shifts in the optical spectra of both mirrors.
Microscopic devices that can move toward specific targets, isolate and detect chemical or biological compounds, and report this information to the macroscopic world could be useful for a variety of environmental monitoring, medical diagnostic, or therapeutic applications. Many of the components needed for such devices are too small or complex to be fabricated by using conventional lithographic tools, and the development of new techniques that can manipulate matter at the nanoscale is currently of great interest. So-called self-assembly reactions provide a convenient means of constructing one-, two-, and three-dimensional objects in this size regime.