A self-healing lens that can stop driverless vehicle accidents

Much common optical equipment, like cameras, mobile phones, and glasses, employ lenses as a tool to capture or distribute light. According to the team, if a scratch damages the "lens surface, the image or optical signal received by the optical device can be severely distorted," said a press note. 

As a counter, this technology helps to solve the issues related to signal distortion by restoring scratches on the sensor surface. The self-healing material optical material helps to increase the product's life expectancy, in turn preventing malfunctions due to surface damage. 

Scratches can be removed in 60 seconds

A transparent lens material was developed by the team, on which, when concentrated sunlight is irradiated with a straightforward instrument like a magnifying glass, has the ability to erase scratches on the sensor surface within 60 seconds.

According to researchers, flexible materials are often helpful in guaranteeing great self-healing performance because self-healing is advantageous when molecular mobility inside the polymer is free. But because lenses and protective coatings are comprised of hard materials, it is extremely challenging to implement a self-healing capability. 

As a solution, the team used a lens material called thiourethane structure and combined it with a transparent photothermal dye to "design a 'dynamic chemical bond' in which the polymers repeat disassembly and recombination under irradiation of sunlight." The photothermal used in this process is able to selectively absorb light of a particular near-infrared wavelength (850-1050 nm) without interfering with the visible light region (350-850 nm) used for image sensors and the near-infrared region (1550 nm) used for LiDAR sensors. 

Increased surface temperature due to the material's exposure to sunlight causes it to self-heal a scratch by "repeating the dissociation and recombination of chemical bonds in the polythiourethane structure." The team claims that it offers perfect self-healing properties and vouches that it works even if the "process of scratching and healing at the same location is repeated more than five times."

Researchers expect that the technology will find widespread applications, with it being primarily used for autonomous vehicle sensors as well as glasses and cameras.