Young_Wheat_crop_in_a_field_near_Solapur,_Maharashtra,_India

Nature’s Designs Inspire Anti-Icing Surfaces

One of the joys I experience as a scientist comes from reading how researchers have discovered features in nature that can help humanity. Mechanical engineers have learned that wheat leaf surfaces are designed to shed large water droplets and remain dry and unfrozen in cold, humid conditions. I’ll explain the discovery and its exciting potential applications in a moment.

Learning from Nature’s Superior Designs
One line of scientific evidence for the Creator-God of the Bible comes from the repeated observations that the designs in Earth’s life-forms are consistently superior to the best designs in humanly manufactured goods. These observations imply that Someone more knowledgeable, intelligent, and powerful than humans must have designed the characteristic features in the different species of Earth’s life. They also imply that copying designs we see in Earth’s life-forms is an efficient way to advance engineering and technology.

In a recent example of a bioinspired technological advance, researchers mimicked the texture in wheat leaves to develop surfaces that remain ice-free even under cold, humid conditions. When I saw the published paper demonstrating how the designs in wheat leaves could be incorporated into manufactured surfaces,1 I immediately thought of a number of benefits that would make my life and the lives of millions of others more productive and enjoyable.

Ice Formation Prevention
Twelve mechanical engineering researchers from the University of Chinese Academy of Sciences (Beijing), the University of California, Los Angeles, and the University of Illinois at Urbana-Champaign carefully studied how wheat leaves prevent the formation and buildup of ice under cold and humid environments. The team cited research2 that established wheat leaves “display self-propelled jumping of micro-droplets and self-removal of contaminants through droplet mutual coalescence, leaving more clean and dry-leaf surface area available for photosynthesis.”3 The microstructure of wheat leaf surfaces possesses a design that causes microdroplets of water to coalesce into large water droplets. The droplets are large enough that surface energy in the wheat leaves, generated through the droplet coalescence, forcefully ejects the coalesced droplets off the wheat surface. The wheat leaf surface design simultaneously elevates the temperature of the leaf surface. Consequently, wheat plants are able to maintain photosynthesis and minimize leaf damage under frost-forming conditions.

Inspired by their studies on wheat leaves, the engineers used an ultrafast pulse laser technology to deposit a thin layer of iron oxide nanoparticles onto a copper surface that perfectly mimicked the porous patterns on wheat leaf surfaces. They then performed a number of experiments that demonstrated that their manufactured surface, under artificial sunlight, stayed dry and kept its surface temperature above water’s freezing point even under humid conditions at –50°C! The previous best lowest temperature water repellency for a manufactured surface was –15°C.4

Applications
The 35°C improvement in prevention of ice formation and ice buildup will make possible several technological breakthroughs. One that was touted in the published paper is the development of aircraft wings and tails that would stay ice-free under all commercial flight conditions. Imagine never having a flight delayed because of the need to remove ice from the wings and tail. Imagine the reduced flight fares resulting from lower fuel consumption. Imagine fewer flight accidents.

In reading the paper, my mind flashed back to all the telescope time I lost because of ice buildup. In the radio astronomy observations I was conducting (in Canada) I noticed that the quality of the data improved by a factor of 3–4 times when the temperature fell below –40°C. Consequently, I applied for all the telescope time I could get during the months of January and February. However, ice buildup on the antenna, and especially on the telescope drive motors, either compromised the data quality or made the telescope inoperable. The metal surfaces manufactured by the twelve mechanical engineers would eliminate these problems.

The new surface technology could make for safer sidewalks, roads, and highways under harsh winter conditions without the use of salt or sand. I recall how in some Canadian cities winter road highway salt would completely corrode the bodies of vehicles in just 4–5 years. Not needing to replace vehicles every 4–5 years would save drivers thousands of dollars and be a boon to the economy.

Anyone who has walked or hiked significant distances under below-freezing conditions will recall the annoyance of frost and ice building up on one’s glasses, parka hoods, and backpacks. I remember, after one long winter hike, not being able to get into my parked car because of ice buildup on the car lock. The new surface technology can eliminate such annoyances and dangers.

More technological applications are certain to be discovered and manufactured. They all provide examples of how the Creator has shown us his designs in nature that we can copy for our benefit and for the rapid fulfillment of the purposes5 for which he created us.

Endnotes

  1. Hongqiang Zhang et al., “Solar Anti-Icing Surface with Enhanced Condensate Self-Removing at Extreme Environmental Conditions,” Proceedings of the National Academy of Sciences USA 118, no. 18 (May 4, 2021): id. e2100978118, doi:10.1073/pnas.2100978118.
  2. Saurabh Nath et al., “‘Sneezing’ Plants: Pathogen Transport via Jumping-Droplet Condensation,” Journal of the Royal Society Interface 16, no. 155 (June 2019): id. 20190243, doi:10.1098/rsif.2019.0243.
  3. Zhang et al., “Solar Anti-Icing Surface,” 2.
  4. Jonathan B. Boreyko and C. Patrick Collier, “Delayed Frost Growth on Jumping-Drop Superhydrophobic Surfaces,” ACS Nano 7, vol. 7, no. 2 (January 3, 2013): 1618–1627, doi:10.1021/nn3055048; Qiaolan Zhang et al., “Anti-Icing Surfaces Based on Enhanced Self-Propelled Jumping of Condensed Water Microdroplets,” Chemical Communications 40 (April 2013): 4516–4518, doi:10.1039/C3CC40592C; Qian Xu et al., “Energy-Effective Frost-Free Coatings Based on Superhydrophobic Aligned Nanocones,” ACS Applied Materials & Interfaces 6, vol. 6, no. 12 (June 2014): 8976–8980, doi:10.1021/am502607e.
  5. I list and describe eleven such purposes in Why the Universe Is the Way It Is (Grand Rapids, MI: Baker Books, 2008), 154–162.