A new study suggests that self-cleaning devices could benefit from new insights into how insects wash pollutants and dirt from their bodies with water droplets.
The waxy surfaces of many living things, like cicadas, geckos, and lotus plants, repel water, allowing morning dew to form perfectly round droplets.
The precise mechanisms by which these droplets from insect wings and plant surfaces meet, jump, and roll, carrying tiny contaminants with them, have now been revealed by scientists.
Experts assert that similar approaches could be utilized to enhance the design and functionality of man-made self-cleaning devices such as biosensors, solar panel coatings, and automobile windshields.
“We now have a better understanding of how to decontaminate surfaces passively without using a power source. This discovery offers a wide range of applications for future research and the development of new experiments for self-cleaning surfaces,”
Dr. Sreehari Perumanathk.
The self-cleaning mechanism on the wings of cicadas was observed by a group of researchers from the School of Engineering at the University of Edinburgh.
They found that pollutants could be removed in two ways, depending on the attraction forces between the contaminant, water droplets, and molecules on the insect’s wings, through computer simulations run on the supercomputer ARCHER2. The review is distributed in the journal Nano Letters.
According to the findings, the pollutant is absorbed by the water droplet when its force exceeds that of pinning the contaminant to the surface. The droplet then rolls or jumps off the wings of the cicada.
In other instances, contaminants will be ejected from the wings in a mesmerizing droplet shape resembling a hot air balloon thanks to the lifting forces produced by a large number of droplets combining.
“We now have a better understanding of passively decontaminating surfaces without using a power source.” According to Dr. Sreehari Perumanathk, “this work has a broad scope for future research and the development of new experiments for self-cleaning surfaces.”
Dr. Matthew Borg states, “This research reveals the critical parameters required for contaminants to be effectively removed from surfaces and opens up new avenues for exploiting precision assembly in future electronics and biosensors.”
More information: Sreehari Perumanath et al, Contaminant Removal from Nature’s Self-Cleaning Surfaces, Nano Letters (2023). DOI: 10.1021/acs.nanolett.3c00257
