BACKGROUND: The rapid miniaturization of technologies behind cameras, cell phones, and wireless computers is allowing scientists to build networks of small sensors that could lead to a new era of ecological insight. For example, UCLA researchers have connected 100 tiny sensors, robots, cameras and computers to monitor the weather and environment. Devices the size of a deck of cards (known as motes, after dust motes) can measure light, wind speed, rainfall, temperature, humidity, and barometric pressure, detecting the presence of a warm body or tracking the progress of a cold wind up a canyon.
HOW IT WORKS: Motes are also known as smart dust or wireless sensing networks. Motes have custom-designed computer chips and sensors that can measure things like temperature, light, sound, position, motion, vibration, stress, weight, pressure or humidity. The computer connects to the outside world via a radio link, so the mote can transmit the data it collects. They are wireless and powered by batteries or (if they are small enough) by solar cells. This means they can be used in remote places. A mote the size of a cell phone can work for five years and transmit up to 325 feet away. The various nodes of a network automatically look for neighboring nodes, and can compensate if a few of them fail.
APPLICATIONS: Environmental sensor networks can help fill an observational gap between microscopes and telescopes. Scientists envision networks of motes being deployed over rain forests or wildlife reserves, or monitoring the water supply in California, for example. Wireless motes, cameras and other sensors deployed in California's James Reserve track the nesting habits of birds, and the life cycles of moss. Robots move along wires strung from tree to tree, lowering sensors to take temperature, humidity and light level readings at different altitudes. Motes could be embedded in concrete bridges to monitor structural integrity, or to machinery to monitor wear and tear before it becomes a problem. Motes attached to water or power meters could log power and water consumption for customers. The military envisions one day using networks of motes to sense and monitor battlefield conditions.
The Institute of Electrical and Electronics Engineers, Inc., contributed to the information contained in the TV portion of this report.