In 2010 radios will cost $0.10. They will be short range (1-100m), low power (10nJ/bit), and low bit rate (1-100kbps). They will be truly single-chip radios, requiring no external components at. MEMS devices will be used liberally for filters and tuneable oscillators. In 2010 scanning 3 color laser projection systems will be no larger than a grain of rice, and cost under a dollar. They will be in augmented reality displays that appear to others as regular glasses. They will be in laser pointers, turning any wall into an electronic whiteboard. They will be in large arrays on walls, forming a truly staggering 3D display with brightness, contrast, and viewing angle unparalleled by any technology available or predicted today. In 2010 everything you own that is worth more than a few dollars will know that it's yours, and you'll be able to find it whenever you want it. Stealing cars, furniture, stereos, or other valuables will be unusual, because any of your valuables that leave your house will check in on their way out the door, and scream like a troll's magic purse if removed without permission (they may scream at 2.4 GHz rather than in audio). In 2010 your house and office will be aware of your presence, and even orientation, in a given room. Lighting, heating, and other comforts will be adjusted accordingly. If you and a colleague are looking for a conference room, you will know which is the nearest available . If you're in an unfamiliar building, lighting will guide you, with a ribbon of arrows on the floor or the walls, annotated with the name of the room they are pointing to, and color coded if there are two lost souls whose paths may cross. In 2010 a speck of dust on each of your fingernails will continuously transmit fingertip motion to your computer. Your computer will understand when you type, point, click, gesture, sculpt, or play air guitar. In 2010 infants will not die of SIDs, or suffocate, or drown, without an alert being sent to the parents. How will society change when your neighbors pool calls your cell phone to tell you that Johnny is drowning and you're the closest adult that could be located? In 2010 your car will know the freeway conditions on your favorite route home, not at the level of some pathetic traffic announcer telling you that it's slow on I5, but with detail of the instantaneous speed and history of every vehicle between you and your destination, as well ast he ones that are likely to get on the freeway, should you choose to look at that detail. Most likely your software will just tell you which route to take, and how many minutes it will take. Your spouse will know too, if you so choose. In 2010 you won't have to hunt for a parking space. You'll call ahead and find (and maybe reserve) the most convenient open space in the lots that you use. In 2010 hunting SCUD TELs in Iraq or T-72s in Yugoslavia will consist of firing up a web browser and proving your authorization. In 2010 everything of any value that you own will have it's own set of sensors, letting you know when your tire pressure is low, the bridge ahead is out (or unsafe), your milk is going bad, or your water heater is about to die. In 2020 there will be no unanticipated illness. Chronic sensor implants will monitor all of the major circulator systems in the human body, and provide you with early warning of an impending flu, or save your life by catching cancer early enough that it can be completely removed surgically. In 2010 MEMS sensors will be everywhere, and sensing virtually everything. Scavenging power from sunlight, vibration, thermal gradients, and background RF, sensors motes will be immortal, completely self contained, single chip computers with sensing, communication, and power supply built in. Entirely solid state, and with no natural decay processes, they may well survive the human race. Descendants of dolphins may mine them from arctic ice and marvel at the extinct technology. Rough Limits ------------ Acquiring a digital data sample from many sensors requires on the order of 1 nJ. Threshold detection at discrete time periods will require substantially less energy in most cases. Higher performance sensors will require more energy per sample, but the nJ/sample number is applicable to, for example: whisper-to-chainsaw acoustic, sub-degree accuracy temperature, milli- to kilo- gravity acceleration sensing (Which also provides tilt and vibration information), magnetic field to 0.1% of earth's field, barometric pressure to 5m, wind flow to 1 m/s, relative humidity to 2%, ambient light level and spectrum. Transmitting a bit of data over 10-100 meters by RF today takes approximately 100nJ with Bluetooth, Wavelan, and other local area RF networks. Transmitting a kilometer takes at 10 to 100 microJoules. These numbers are not likely to fall much, since they are often pushed up close to the fundamental physical limits. Another order of magnitude may be available by sacrificing immunity to unintentional jamming from nearby transmitters. If the dynamic range of the radio receivers is reduced, substantial improvements inpower can be realized. Collimated line-of-site optical communication systems will transmit 10m with an energy cost of 10pJ/bit, more than 10,000 times lower than existing radio technology. We have demonstrated 1nJ/bit in the lab already. This incredible gain over RF is due entirely to an antenna gain of roughly 7 orders of magnitude when going from an isotropic radiator to a 1 mrad divergence beam. 32 bit computation currently costs around 1nJ/instruction on power- optimized microprocessors. Engineering limits in the next 5 years or so are approximately 1pJ/instruction for dedicated hardware. Good batteries provide roughly 1 J/mm^3 . Solar cells provide approximately 100uW/mm^2 in full sunlight, more than 100nW/mm^2 in average room lighting. Vibrational energy availabe in an office setting is in the nW/mm^3 range. RF power in a simple antenna is generally not useful, unless there is a cell phone in use in the room, or a dedicated RF power source, in which case microWatts can easily be generated. Conversion is difficult, but feasible. Assuming a simple task of sampling a sensor, performing some relatively simple processing (threshold, FIR/IIR filtering, statistical analysis, or FFT), listening for incoming messages, and transmitting a simple outgoing message, the energy cost will be a few nanoJoules. Combining this with the power source information, a cubic millimeter battery will provide enough power to perform such a simple task once a second for 10 years. A cubic millimeter vibrational energy rectifyer will operate at that rate forever. Indoors a square millimeter solar cell will provide enough power to perform 100 tasks/second, or in full sunlight 100,000 tasks/second. For indoor optical line of sight communication, a cubic millimeter battery will provide enough energy to transmit 50 billion bits (roughly half a dozen full-length movies).