been created and marketed. "Touch-plate" devices can be operated by touching or merely waving a hand near the switch. Touch switches have no moving parts and electronically switch the light circuit. these remain specialty items. Electronic switches provide flexibility in terms of different interfaces for their operations, such as touch plates, soft-touch controls, pressure or light sensor based control, interactive touch-screens (which are widely used in aircraft for lighting control), and others. Public buildings such as hospitals frequently save energy by using motion detector switches, also known as occupancy sensors. The occupancy sensors can also be used in residential applications such as in bathrooms, garages, and hallways. A wireless light switch provides remote control of lighting using a hand-held transmitter. While the controlling device may be a unit dedicated to this purpose, increasingly such switches may be controlled by the technology (such as Bluetooth or Wi-Fi) now found in smartphones. Wired remote control of lighting switches is also possible using, for example, X10 signaling over the power wires. Multiway switching Two or more light switches can be interconnected to allow control of lighting from, for example, two ends of a long hallway or landings at the upper and lower landings of a flight of stairs. Multiway switching is done using special switches that have additional contacts. Materials Earlier switches were made of porcelain in the surface-mounted version and operated as a rotary switch with a rotary mechanism. Later, more durable Bakelite and Ebonite was used. Today they are made of modern plastics, like Polycarbonate or fire resistant ABS. Some switches may also be manufactured from other plastics like polyamide, polypropylene or pvc but mainly limited to wire mounted switches (like night lamp switches) mainly due to reduced weight, and most such switches are not used in high power devices (mainly table lamps, table fans, some radios) mainly up to 2 amperes. In some cases, especially in hospitals and other public facilities, exposed parts of light switches are made of antimicrobial materials such as copper, for infection control. See also Touch-sensitive lamp References External links Switches 19th-century inventions British inventions