In 1962, the chemist Steven Kistler developed a type of reinforced glass called Chemcor, which used a process called sodium/potassium ion exchange to make it more durable. This technique involved swapping smaller sodium ions on the glass's surface with larger potassium ions, creating a compressed layer that made the glass more resistant to damage. However, Chemcor did not gain widespread popularity and was eventually set aside by Corning, the company behind it, in 1971 due to limited market demand and high production costs. The development of Chemcor was part of a larger research effort at Corning, which had launched an internal project in the early 1960s called Project Muscle. This initiative aimed to create a glass that could withstand significant impact without breaking. By 1961, researchers had created a version of this glass that was sold under the name Chemcor. The real innovation came in 1962 when Kistler refined the ion exchange process, making the glass even stronger and more durable. Despite its technical merits, Chemcor never became a mainstream product for the general public. It found use in niche markets like automotive, aviation, and pharmaceutical industries, such as in a few models of Dodge Dart and Plymouth Barracuda cars in 1968. However, the automotive industry at large did not adopt it due to cost concerns and the lack of a large enough market to justify mass production. As a result, Corning halted the project in 1971. Nearly four decades later, in 2005, Corning quietly revived its research, this time with a specific goal in mind: creating a thin, durable glass for electronic devices. This renewed interest was partly driven by Steve Jobs, who, while working on the first iPhone, discovered that the originally planned plastic screen was too prone to scratches. He approached Corning for a solution, prompting the company to adapt its earlier research. The result was a new formula, different from the original Chemcor, which became known as Gorilla Glass. Two years after the project was relaunched, the first generation of Gorilla Glass was used in the first smartphones to reach the market. Since then, Gorilla Glass has continued to evolve, becoming thinner and more resistant to scratches, shocks, and bending. Today, it is estimated that this material, which originated from the research conducted in 1962, has been used as protective glass on more than 8 billion mobile devices worldwide.