ays Engel. The researchers have already crafted such sensors by depositing metal films on flexible polymer substrates. Besides keeping tabs on a building's health, potential smart brick applications include various other types of monitoring chores. "In the gaming industry, wireless sensors attached to a person's arms and legs could replace the conventional joystick and allow a 'couch potato' to get some physical exercise while playing video games such as basketball or tennis," says Liu. "The opportunities seem endless." 3.5 WIRELESS SMART STUFF Wireless networks, along with improvements in processor, software, and related technologies, will lead to the arrival of smart appliances. A smart appli- ance is a household device that supplements its basic function, such as keeping food cold, with internal intelligence and external communication capabilities. A smart refrigerator, for example, could keep track of product quantities and expiration dates, via a code embedded into the product packaging, to make sure that there's always an ample and fresh supply of food and bever- ages. Using a wireless link to the home's central server, a smart refrigerator could automatically notify its users of products that must be purchased on the next shopping trip. The refrigerator could even place orders directly to merchants for home delivery. By 2025, smart refrigerators, as well as smart toasters, microwave ovens, washing machines, clothes dryers, and dish washers, should all be commonplace. Wireless broadband links between TVs, stereos, household appliances, and other devices will allow information and entertainment systems to share data, making them all highly interoperable. Forget about searching for a favorite song or movie-the files will be stored inside the home's central server. The server will also allow users to manage all connected devices through table-top and wall-mounted displays, as well as portable devices. CONNECTIONS IN THE AIR-WIRELESS TECHNOLOGIES We can also expect the home of tomorrow to be equipped with camer