New optical lens coating is ‘self-cleaning’ and anti-fogging

Researchers at Nanyang Technological University, Singapore have developed a new optical lens coating that is self-cleaning and prevents fogging. The scientists believe their new product will prevent the need for frequent reapplications.

The coating is highly durable due to its construction – a thin double layered silicon dioxide and titanium dioxide film applied in a two-step method. When applied to plastic lenses, the coating disperses water droplets in 93 milliseconds, 7 seconds faster than the average blink.¹

The film’s uniform droplet pattern is what works to prevents fogging. The plastic surface is first treated through a process known as oxygen plasma – an industrial method of cleaning surfaces and improving adhesion.¹ The coating is then deposited on the surface layer using a laser beam.¹

Applications

The research team reports that the new coating might be used for a wide range of applications, including eyeglasses, solar panels and surveillance cameras.¹ They noted that the new coating can also break down dirt and bacteria by tapping into ultra-violet light for a full day.

The development of such coatings for industrial purposes has been hindered by their durability in the past. This is because previous versions could not withstand washing and had to be reapplied often due to poor adhesion.¹

The old coatings also required more time to apply and were more susceptible to surface contamination from dirt and bacteria.¹ Both problems are solved with the new coating formulation, which takes less than an hour to apply and is more resilient, according to researchers.¹

The international materials science journal, Applied Surface Science, published the teams findings in December 2021.²

Resources

1. Soh G. NTU develops new 'self-cleaning' anti-fogging coating. The Straights Times. February 22, 2022. Accessed March 8, 2022. https://www.straitstimes.com/singapore/environment/new-self-cleaning-anti-fogging-coating-developed-by-ntu

2. Ye Sun, Rajdeep Singh Rawat, Zhong Chen. Mechanically robust multifunctional antifogging coating on transparent plastic substrates. Applied Surface Science, 2022; 580: 152307 DOI: 10.1016/j.apsusc.2021.152307