Power isn't enough for us. We want power wherever we go. We use millions of portable electrical devices every day and most of them draw their power from the humble battery. It was invented in 1800 by Italian physicist Alessandro Volta, who named his creation the Voltaic Pile. Volta's breakthrough came when he generated an electric current by submerging copper and zinc strips in salt water.
THE BAR CODE
Bernard Silver and Norman Woodland were postgraduate students at Philadelphia's Drexel Institute of Technology in 1949 when they began to research a system that would automatically collect product information at retail checkouts. The original version used thick and thin lines arranged in a concentric circle. It was years before IBM eventually developed a reliable bar code scanner. The first item to be sold using a bar code was a packet of chewing gum, in an Ohio supermarket on June 26, 1974.
THE BALLPOINT PEN
The idea of a ballpoint pen was first patented by American John J. Loud in 1888 but he couldn't get the ink to flow properly. During the 1930s, Laszlo Biro, a Hungarian artist and journalist, began working on a ballpoint pen that used printers' ink, which was thicker and quicker-drying than conventional ink. Biro teamed up with a British government official, Henry Martin, in 1943 and the first Biro pens were made for the RAF in 1944.
THE POST-IT NOTE
Post-it Notes are one of those inventions that we didn't think we needed until they were invented. Now, we use them all the time. The product was invented in 1974 by American Arthur Fry, who worked for the 3M Corporation. Fry conceived Post-it Notes after making sticky bookmarks for his hymn books, using a weak glue developed by a 3M research chemist, Spencer Silver. By the time Post-it Notes went on sale in 1980, the product had evolved from a sticky bookmark to a temporary note after it became clear that employees couldn't stop themselves writing on the prototypes.
THE MICROWAVE OVEN
This inoffensive kitchen appliance was developed from a military radar system. American Percy LeBaron Spencer was working for the Raytheon manufacturing company in the 1940s when he noticed that a bar of chocolate in his pocket had been melted by a nearby radar device known to emit microwaves. Spencer experimented further with a bag of corn kernels: within seconds they became popcorn. A patent was granted in 1950 and a Boston restaurant began using the first microwave oven a year later.
THE RING PULL
Tin cans were a great way of preserving and packaging beverages but getting at the drink inside was a pain. You needed to punch two holes in the top - one to drink out of and the other to vent the can. American Ermal Fraze patented an idea for a drinks can with a tear-strip in 1963 but his rectangular tab was difficult to grip. In 1965, Omar Brown and Don Peters designed a ring to pull away the tear-strip and the ring-pull was born. In 1975, Brown and Fraze patented the modern, "push-in" ring-pull, which did away with the sharp litter the original design had created.
In 1961, South African-born Ron Hickman was working as a designer for Lotus Cars in the UK. During a weekend DIY session, he accidentally sawed into a dining chair he'd been using to support his work. The incident inspired the invention of the Workmate portable workbench. More than 40 years later, the device is still an invaluable part of the DIY toolkit in millions of households. Black&Decker rejected the Workmate when Hickman first approached the company. He'd been manufacturing Workmates independently for four years before Black&Decker struck a licensing deal in 1972.
THE STICKING PLASTER
American Earle E Dickinson had an accident-prone wife. He worked for medical supplies manufacturer Johnson & Johnson, though, so there was always plenty of surgical adhesive tape and gauze around the house. He began making pre-prepared dressings by sticking pieces of gauze on to a roll of adhesive tape. In 1920, he invented the sticking plaster. A year later, his employers launched the product commercially, in roll form. Sticking plasters really took off in 1924, when Johnson & Johnson began selling them as pre-cut strips.
One night in 1933, road contractor Percy Shaw was driving back to his home in Halifax along an unlit road. He saw his headlights reflected in the eyes of a cat, showing him where the edge of the road lay. The encounter prompted him to begin development of a reflecting road stud. He set up a company to manufacture his device in 1935 and was granted a patent in 1936. Shaw wasn't the only inventor working on road studs, but his were the best. The reflective lenses were forced into a rubber housing when a car passed over them. Once the car was gone, the lenses popped out again in a self-cleaning action. Impressed, the British government adopted Shaw's design just in time for the World War II blackout.
THE PARKING METER
Where would we be without parking meters? A lot better off, some might say. Nevertheless, they're an integral part of modern life. American Carlton C Magee filed the first patent for a parking meter in 1932. The first parking meters went into operation in Oklahoma City, in 1935. The devices were installed experimentally in Britain in 1955, before being adopted permanently by Westminster City Council in 1958. Traffic wardens first appeared on the streets of New York and London in 1960.