Patents are the DNA of inventions, spawning entire new industries, businesses and economies. A new study by the Brookings Institution finds the most productive periods in the United States occurred during the early 20th century and the Great Depression. There’s also been a patent boom in the past four years and the rate of patenting is nearly as high today as at any time in U.S. history. The most patents (per capita) came in 1916, 1915, 1885, 1932, 2010, 2011, 1931, 1883, 1890, and 1917. Here’s a look at some inventions from those years:
1883: Thomas Edison's Voltage Regulator
Superstar-inventor Thomas Edison has claimed more than 1,000 patents, including the phonograph, light bulb and this electronic device that was key to the development of radio, television and computer transistors.
1885: Machine Gun
American-born British citizen Hiram Maxim invents a self-powered portable and fully-automatic machine gun that changes warfare. Its effects on society and the constitutional right to own it are still being debated today.
1890: Stop Sign
William Phelps Eno proposed the first set of traffic rules and signs in an article in Rider and Driver, although the first actual sign didn’t appear until 1915.
1915: Stainless Steel Sink
The discovery of a new “rustless” steel by British metallurgist Harry Brearley is announced in the New York Times. Brearley applied for a patent that year, but American Elwood Haynes beat him to it. Its shiny surface, strength and corrosive resistant properties revolutionized modern industry from skyscrapers to kitchen utensils, trains and planes to medicine.
1916: Condenser Microphone
Edward C. Wente of New Jersey’s Bell Labs invents the electronic condenser microphone, which can be found today in recording, television, film and radio studios.
1917: Modern Zipper
Gideon Sundback figures out that 10 fasteners per inch works much better than four and invents the modern zipper, or “separable fastener.” Used to close boots and tobacco pouches, the zipper doesn’t get into clothing for another 20 years.
1931: Stop-action Photography
Harold “Doc” Edgerton began playing around with strobe lighting while a grad student at MIT, developing both stop-action and ultra-high speed photography. His images of exploding bullets, running athletes and milk droplets became iconic photos. He went on to invent underwater time-lapse photography, atomic bomb timing and lights for copiers and flash photography.
Edwin Land invents the polarizer, which filters light waves and reduces glare. He goes onto invent instant photography, while the polarizer leads to sunglasses, camera filters and LCDs.
Apple debuted its iPad tablet in April 2010. Its history goes back to 1983, when Apple CEO Steve Jobs said he wanted to build a computer that users could carry around like a book, plug into telephone communications and link to libraries and other databases. The firm sold 23 million in the last quarter of 2012; total sales now top 100 million.
2011: Stark Hand
This prosthetic hand is cheaper, lighter and doesn’t need wires or batteries. Garage inventor Mark Stark came up with this device to help a neighbor who had been born without a hand. It's now under commercial development.