Smart Dust
Contents What is Smart Dust? How its work? History of smart dust. Smart Dust Mote Introduction Architecture Smart Dust Components Measurement, characteristic, & working of smart dust Communication with Smart Dust Application Challenges Conclusion
Introduction Smart dust is a tiny dust size device with extra-ordinary capabilities. Smart dust combines sensing, computing, wireless communication capabilities. Have power supply within volume of only few millimeters and that too at low cost. These devices are proposed to be so small and light in weight that they can remain suspended in the environment like an ordinary dust particle.
What is Smart Dust? "Smart dust" devices are tiny wireless micro electro mechanical sensors (MEMS) that can detect everything from light to vibrations. Nodes in Smart Dust are called Motes. These "motes" contain sensors, computing circuits, bidirectional wireless communications technology and a power supply integrated on a tiny dust size-device.
History of Smart Dust Smart dust was invented in 2001 by Kristopher S. J. Pister, who is an electrical engineering and computer science professor for the University of California The DARPA (NASA) has been funding Smart Dust research heavily seeing virtually limitless applications in the sphere of modern warfare. In 2001 In 2008 Kristofer S. J. Pister
Mote & its operation Smart dust device is run by microcontroller. It read the data coming from sensors and stores in SRAM.
Operation of mote The microcontroller will use the corner cube retro reflector (ccr) or laser to transmit sensor data or a message to a base station or another mote. This allows the user to change the behavior of the mote remotely. The laser diode contains the onboard laser which sends signals to the base station by blinking on and off. The corner cube retro reflector, transmits information just by moving a mirror and thus changing the reflection of a laser beam from the base station.
Making of Smart Dust
Architecture A single Smart Dust mote has: A semiconductor laser diode and MEMS beam steering mirror for active optical transmission. A MEMS corner cube retro-reflector for passive optical transmission. An optical receiver. A signal processing and control circuitry. A power source based on thick-film batteries and solar cells.
Architecture
Smart dust component
Measurement of Smart Dust These are made by Hitachi. They measure only.15.15 mm each and have GPS capabilities. Sometimes called smart dust as they can be sprayed on us and absorbed or taken in foods, drinks and even injected.
Working of Smart Dust Primary constraint of smart dust is volume. Most of the time mote if off with only timers running. Run by microcontroller. Determines the task performed by the mote. Controls power. When a timer expires, it powers mote to carry out a job, then powers off.
Smart Dust. Device
Characteristics of Smart Dust Besides the functionality it has bi-directional radio, the microprocessor controller, and the battery. It has 20 meter communication range It has one week lifetime in continuous operation, 2 years with 1% duty cycling. Current motes are about 5mm
Key Features of these electronic particles * Power - Survive for extended amount of time * Computation Process Sensor Data and Communicate * Sensors - To Interface to the environment *Communication - To glue the pieces of information
Power - Big Problem - Low capacity per unit of mass and volume Solar Vibration Power: Lithium Battery - Needs support by sleep mechanism and low power techniques Acoustic noise Thermal conversion - Not really so much innovation after Volta! Nuclear Reaction Fuel Cells
Computation Computation: ATMEL91M404000 Micro Controller FPGA -Core and variety of different functions -Flash, SRAM, E2PROM -GPIO, ADC, PWM,Comparator -Embedded serial Buses -Ex: Microcontrollers Atmel, Microchip, Motorola Microprocessors Intel Strong-Arms,Motorola Not Traditional Style Of programming Hardware Descriptive Languages (VHDL, Verilog) Faster, Low Power, Reconfigurable Ex: Xilix, Atmel
SENSOR Motion Sensing - Magnetometer - Accelerometer Environmental Sensing (Weather Monitoring) - Pressure - Temperature - Light - Humidity
Communication Technologies Radio Frequency Transmission Optical transmission technique a) Passive Laser based Communication b) Active Laser based Communication c) Fiber Optic Communication
Radio Frequency Transmission Based on the generation, propagation and detection of electromagnetic waves with a frequency range from tens of khz to hundreds of GHz. Multiplexing techniques: time, frequency or code-division multiplexing. Their use leads to modulation, band pass filtering, demodulation circuitry, and additional circuitry, all of which needs to be considered, based on power consumption.
Problems with RF communication Large size of antenna. RF communication can only be achieved by using time, frequency or code division. TDMA, FDMA, and CDMA have their own complications.
Passive Laser Based communication Downlink communication (BTS to dust)- the base station points a modulated laser beam at a node. Dust uses a simple optical receiver to decode the incoming message Uplink communication (dust to BTS)- the base station points an unmodulated laser beam at a node, which in turn modulates and reflects back the beam to the BTS
Active Laser Based communication Has a semiconductor laser, a collimating lens and a beam-steering micro-mirror. Uses an active-steered laser-diode based transmitter to send a collimated laser beam to a base station. Suitable for peer-to-peer comm.., provided there exist a line of sight path between the motes.
Fiber Optic communication Employs semiconductor laser, fiber cable and diode receiver to generate, transfer and detect the optical signal. Similar to passive optical communication. Relatively small size of the optical transceiver is employed with low-power operation. CCR employed on each Dust mote to modulate uplink data to base station.
Medical application Enter human bodies and check for physiological problems. Relay information about cancerous cells. Biomedical application Artificial Retina.. Environment monitoring Indoor/Outdoor Environmental Monitoring. Environmental protection (identification and monitoring of pollution). Applications
Applications Military application Monitoring activities in inaccessible areas, accompany soldiers and alert them to any poisons or dangerous biological substances in the air. IT Sector Accelerometer containing Smart Dust MEMS microphones in portable devices Monitor speed and Volume of traffic to avoid recurring traffic jams. Virtual Keyboard SMART DUST
Major Challenges As the devices are so small, batteries present a massive addition of weight. It is difficult to fit all these devices in a small Smart Dust both size wise and Energy wise.
conclusion There are many ongoing researches on Smart Dust, the main purpose ofthese researches is to make Smart Dust mote as small as possible and to make it available at as low price as possible. Soon we will see Smart Dust being used in varied application from all spans of life.
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