Edison’s 1879 Light Bulb May Have Made Graphene by Chance

Thomas Edison worked in his Menlo Park lab in New Jersey back in 1879 to build a light bulb that would last. He used carbon filaments from Japanese bamboo and heated them with electricity to make light. Now, scientists at Rice University say those filaments turned into graphene, a super-thin sheet of carbon atoms, during his tests.

Background

Edison set up his lab in Menlo Park as one of the first places to do organized research. He tested over a thousand materials for filaments before landing on carbonized bamboo from Japan. His bulb, patented that year, could burn for 13 hours straight, a big step up from earlier tries that lasted minutes.

The process involved hooking the filament to a 110-volt DC power source. When switched on, the filament got very hot, around 2,000 to 3,000 degrees Celsius. That heat made it glow and produce light for homes. Edison made thousands of these bulbs to show they worked in real life.

Graphene stayed unknown back then. A physicist named P.R. Wallace first described it in theory in 1947. It took until 2004 for Andre Geim and Konstantin Novoselov to pull it from graphite with tape, earning them the Nobel Prize in physics in 2010. Graphene is just one atom thick, stronger than steel, and clear. It shows up in phones, batteries, and sensors today.

Edison died in 1931, long before anyone knew about graphene. His bulbs used carbon, not tungsten like today's bulbs. The heat came from something now called flash Joule heating, where electricity zaps carbon fast to change its structure.

Key Details

Rice University chemist James Tour and his team wanted cheap ways to make graphene from everyday stuff. Lucas Eddy, a former student in the lab, led the work. He tried arc welders and even trees hit by lightning but got nowhere.

Finding the Right Bulbs

Eddy thought of old light bulbs. He needed ones like Edison's, with real carbon filaments. Many replicas had tungsten hidden as carbon, but tests showed the truth. He found artisan bulbs in a New York City art store. They used Japanese bamboo filaments, just 5 micrometers thicker than Edison's originals.

Eddy wired the bulb to 110 volts DC and turned it on for 20 seconds. Any longer, and the graphene turns to graphite, a stacked form of carbon. Under a microscope, the filament shifted from dark gray to shiny silver. That hinted at a change.

To check, they used Raman spectroscopy. This method shines lasers on a material and reads its atomic pattern like a barcode. It started in the 1930s but got better over time. The results showed turbostratic graphene, where layers sit at odd angles, not stacked neatly.

The team published their findings in ACS Nano this month. They matched Edison's 1879 patent exactly for the setup.

"To reproduce what Thomas Edison did, with the tools and knowledge we have now, is very exciting," said James Tour, the T.T. and W.F. Chao Professor of Chemistry and corresponding author on the paper. "Finding that he could have produced graphene inspires curiosity about what other information lies buried in historical experiments."

Eddy called it a light bulb moment when he remembered carbon filaments. His lab mate joked about that. The short zap kept it as graphene, unlike Edison's long burns that would graphitize it.

Limits of the Original Tests

No one can test Edison's actual bulbs today. Museums have some, but the filaments ran for hours and turned to graphite. Any graphene from the start would be gone. The Rice work shows what could have happened under those conditions.

What This Means

This links old inventions to new tech. Graphene helps make faster chips, bendable screens, and better batteries. Making it cheap matters for wide use. Flash Joule heating uses waste carbon like food scraps or rubber tires, not pure graphite.

Revisiting Edison opens doors to other past work. What else did early scientists make by accident? Tour asks what questions old inventors would pose today. It pushes labs to look back with new tools.

The find spotlights Edison's trial-and-error style. He failed a lot but kept going. His bulb changed homes forever. Now, it ties to a material changing tech again.

Rice's method scales up. They make grams of graphene fast from junk carbon. That cuts costs from dollars per gram to cents. Companies eye it for electronics and energy storage.

Scientists plan more tests on historical setups. Victorian-era batteries or early motors might hold surprises. Raman and microscopes let us see what eyes missed before.

Eddy's path shows how ideas connect. From mass production worries to a 145-year-old patent. It proves science builds on itself, even across centuries.

The paper notes keywords like Joule heating and turbostratic graphene. Those terms guide future work. Labs worldwide may try similar recreations on forgotten experiments.