10 Best Nikola Tesla Inventions

After dying penniless and nearly forgotten in 1943, the extraordinary Nikola Tesla now enjoys a permanent spot in the inventors hall of fame. Born in Serbia (now Croatia) in 1856, the eccentric, visionary Tesla is credited with some of modern history's most consequential inventions. As noted by "Tesla: Inventor of the Modern," entrepreneurs like Elon Musk and Google founder Larry Page regard Tesla as a folk hero as well as the father of electricity, radio, and robots. His name has become synonymous with innovation and genius. In addition to the airport in Belgrade and Musk's electric car company, notes Business Standard, units of measure in MRI scanners bear Tesla's name, and the coil he invented in 1891, still in use today, is called the Tesla coil.

Not surprisingly, the story of Tesla's inventions is as complex as the man himself. Attributing inventions can be tricky, as it's common for multiple inventors to be working on similar ideas simultaneously. Tesla, who immigrated to America at 28, held hundreds of patents, but his career was crippled in part when a fire in his New York laboratory destroyed much of his research, forcing him to file for patents late or to modify their applications. Financial setbacks also hampered his ability to finish projects. Consequently, in some cases, other inventors ended up receiving credit for inventions and breakthroughs Tesla completed first. Recent historical research, however, has led to a reassessment of Nikola Tesla and his inventions.

As explained in How Stuff Works, to create mechanical energy, engines require some form of liquid that will flow under an applied stress. Engines of the early 20th century applied stress on liquid either through pistons or bladed turbines. Piston engines were complex, heavy, and inefficient, and while bladed turbine engines had few moving parts, the blades required careful installation and tended to break and crack. Nikola Tesla, in fact, was inspired to create his bladeless turbine after seeing bushels of broken blades dumped from a turbine-equipped ocean liner.

Tesla's invention consisted of designs for three separate components — fluid propulsion, turbine, and valvular conduit — that when combined produced a highly efficient bladeless turbine. In a 1913 Patent Office application (via Tesla Universe), Tesla stated that his turbine would overcome the deficiencies of the bladed turbine by "propelling fluid to move in natural paths or stream lines of least resistance." To achieve these stream lines, as he noted in a 1911 New York Herald interview (via Rex Research), all that was needed was "some disks mounted on a shaft, spaced a little distance apart and cased so that the fluid can enter at one point and go out at another."

Tesla's turbine design was simple, but because it used centrifugal force, extra durable materials were needed for construction. Consequently, it was never put into commercial use. However, engineers today continue to experiment with it in the hope that its visionary technology can be exploited for greater energy efficiency.

According to PBS, in 1893, after a long and contentious search, the Niagara Falls Commission awarded Westinghouse Electric and, by extension Nikola Tesla, a contract to construct a powerhouse to harness the energy of the falls. As noted in "Tesla: Inventor of the Modern," Westinghouse bested the competition in large part because Edward Dean Adams, the project's lead engineer, and renowned British physicist Lord Kelvin, the commission's head, were fans of Tesla's AC electrical generator, the main component in Westinghouse's proposal for the powerhouse.

For his part, Tesla had long been fascinated by Niagara Falls. As a young boy in Serbia, Tesla had seen an engraving of the falls in his classroom and declared to his teacher that someday he would go to America and build a "big wheel" to capture the water's power. Although small-wheel technology was initially considered for the project, Adams eventually decided to divert water from the Niagara River through huge pipes that would feed into a series of turbines, which in turn would activate two of Tesla's giant AC-powered generators.

Construction of the powerhouse lasted three treacherous years. Finally, on November 6, 1896, the power switch in Niagara Falls was thrown, and 22 miles away in Buffalo, streetcars and streetlamps started lighting up. Soon, the Niagara powerhouse was illuminating New York City, 400 miles away. Tesla's hydroelectric generators had become the center of the world's first power plant, and he was honored with statues on both sides of the Falls. 

In 1898, during the Electrical Exposition at Madison Square Garden, Nikola Tesla presented a demonstration of his latest invention, the teleautomaton. As noted in PBS, Tesla used radio signals channeled through a battery-powered remote control device — a small box with levers on the side — to guide a toy boat. According to "Tesla: Inventor of the Modern," the inventor envisioned teleautomatics (now known as robotics) as a way to control electromechanical devices wirelessly and from a distance.

At the Garden, as a rapt audience of scientists, investors, and the general public watched, Tesla launched his little boat in a small pool, using the remote control box to maneuver it back and forth and dance around in the water. Tesla even "asked" it what the cube root of 64 was, then flashed its lights four times in response. Some stunned spectators accused Tesla of using magic or telepathy to control the boat, and Tesla later wrote that his teleautomaton created a "sensation such as no other invention of mine has ever produced."

Although the invention was not exploited at the time, not even by the military, its technology was later used in drones and TV remotes and was instrumental in the development of robotics. When asked by a reporter about possible applications of the teleautomaton, the inventor prophetically declared, "You see there the first of a race of robots, mechanical men which will do the laborious work of the human race."

Who created the radio star? Tesla! As noted in Live Science, radio, television, and mobile phone communication is derived from radio waves, which occur as electromagnetic radiation. Radio waves are measured by the frequency with which they pass through a fixed location, and when they're transmitted to a receiver, they're converted to "mechanical vibrations in the speaker to create sound waves." According to PBS, in the early 1890s, Nikola Tesla, using his new coil invention, discovered he could send and receive radio signals that were tuned to resonate at the same frequency, because "when a coil is tuned to a signal of a particular frequency, it literally magnifies the incoming electrical energy through resonant action." St. Louis reports that Tesla first publicly demonstrated a simple version of his invention at the 1893 National Electric Light Association Convention in St. Louis. By early 1895, he was preparing to send his radio waves 50 miles to West Point, New York.

Unfortunately, before the West Point demonstration, Tesla's radio design was destroyed in the same lab fire that claimed his shadowgraph plans, delaying the filing of his patent application. Tesla and the well-connected Italian inventor Guglielmo Marconi, who received the first wireless telegraphy patent in England in 1896, then began a long battle for U.S. patent rights. Although Marconi's radio design actually included an oscillator designed by Tesla, Marconi prevailed in patent court in 1904. However, in 1943, the Supreme Court upheld Tesla's patent, thereby posthumously awarding him radio invention bragging rights.

Nikola Tesla's invention of the alternating current (AC) electrical system was undoubtedly his most significant, both in terms of social impact and scientific advancement. According to Britannica, alternating current is a "flow of electric charge that periodically reverses." First discovered by English scientist Michael Faraday, AC electricity, when harnessed, can transmit "power over large distances without great loss of energy due to resistance."

As noted by PBS, when Tesla arrived in New York City in 1884, incandescent lighting, as powered by Thomas Edison's power station, had been in use for several years. The station used direct current (DC), which had proven to be inefficient and dangerous. The youthful Tesla took a job with Edison, his idol, and suggested that the AC motor he was designing might be a safer, more efficient option than DC. Edison balked at the idea, and after a disagreement over money, Tesla quit Edison's company.

Later, with money from various backers, Tesla realized his AC power design dream, and in 1887, he filed seven patents for polyphase AC motors and power transmission. These accomplishments brought him to the attention of Edison's rival, George Westinghouse, who hired Tesla to devise a new form of long-distance power transmission. At that point, the War of the Currents, as it came to be called, began. Using publicity stunts and lawsuits, Edison attacked Westinghouse and AC for years. Eventually, AC emerged as the preferred method of electrical transmission, and continues to be used around the globe to this day.