Nature behind science
The day is not too far when you will be able to hang upside down just with one hand from a roof or climb up a wall of a building like Peter Parker in Spiderman. I am not sure why you would want to do that but it sure will be an awesome thing as far as science is concerned. So, what inspires mankind to aspire to such things? Naturally and obviously nature. The design and creation of nature is incredible, inspirational, magical, charismatic infact even if we use all the superlatives in oxford dictionary it will still be sufficiently inadequate. We may be able to understand fully how a heart beats, but we will possibly never know why it beats anyway. So, till somebody figures it out it’s wiser to turn to beloved ones and say, “my heart beats for you”. Good for us.
And, next time if you see someone, shamelessly peeing on a roadside lotus leaf under the influence of alcohol please try to remind him, provided he is in a state to understand anything, to watch a marvel of nature; at least. He can’t wet that leaf a bit, I bet. The water drops will just roll away, infact washing dirt and filth as it descends. If you want to impress somebody, call this effect of lotus leaf ‘superhydrophobicity’. Inspired by this amazing self cleaning tendency of lotus leaves, a large section of the scientific community is trying to make a windshield glass that doesn’t need wipers. Perhaps in my old age I will be able to drink hot tea during winters in Darjeeling without having to worry about fog on my ‘superhydrophobic’ spectacles or drive home from siliguri on national highway 31A in a latest model tata nano of that age with ‘self-cleaning’ windshield and exterior. Only thing I would probably need to activate the self cleaning mode is some rain, which is not a problem in Darjeeling.
Science behind nature
In layman’s term superhydrophobicity roughly translates into: hate against water. So, what makes an innocent looking lotus leaf so hateful against water?
According to a research paper published in science (2007), “superhydrophobic character of lotus leaf surface is attributed to a combination of surface chemistry and roughness on multiple scales”. So are we to believe that its surface is ‘slippery’ (for water droplets) because it is rough? Surprisingly the answer is almost yes, even though it might sound like asking someone to believe that scratching a carom board and making it ‘a little bit’ rough can help a striker (goti) slide well.
But before our logic gets that far (and that much worse), it must be quickly emphasised that the ‘roughness’ in a lotus leaf is in the nanometres and micrometers scale which is small enough to defy any logic based on macroscopic scale. The roughness in this scale has rather been found to reduce ability of a droplet to spread out. It compels the droplets to stay as spherical as possible, eventually making it to carry dirt and filth away as it rolls down to the ground. Besides roughness, a special water repelling wax present on the surface is also a crucial factor that makes the lotus leaf stand out. Barthlott and Neinhuis where the first ones to reveal what they called ‘lotus effect’ and they patented this concept of self cleaning surface in the 90s. Based on this, a German company ispo GmbH has reportedly developed a self cleaning paint that claims to keep buildings clean with a little bit of help from the rain.
Lizard behind Spiderman
When it comes to understanding the ability to climb walls like Spiderman, interestingly a Gecko (a small sized lizard) has inspired us more than the spider itself. So much so that science writer Peter Forbes has named his entire book after the gecko’s foot: The gecko’s foot. Bio inspiration: Engineered from nature. If scientists can make Peter Parker a reality someday, I personally feel he would be more of a Geckoman than of a Spiderman, unless of course they incorporate authentic web throwing machines in the synthetic costume of the superhero entirely inspired from spiders.
To quote Helen R. Pilcher in a nature news article, “Gecko’s are famed for their wall climbing antics and their ability to hang from the ceiling by a single toe. They can do this because their digits are covered in millions of tiny hairs that bond any surface”
In fact each hair produces only infinitesimally small attraction with the surface, but when the millions of hairs act together it creates an adhesion strong enough to attach the Gecho on the ceiling or walls, one handed. Doesn’t it remind us that even in microscopic scale unity is still strength?
Inspired by geckos, Scientists from Manchester University have already developed a synthetic ‘gecko-tape’ that can potentially stick a person to the ceiling by just one hand. But commercial exploitation is limited by its high production cost. Anyway, cling on to life friends there are plenty of crazy things coming up in the market!
Acknowledgement: Thanks to Natalie Gruenke for helping me with manuscript correction.
This article is my personal take on recent developments in science and technology and is based on my academic knowledge, research experiences and reports I have read in various research papers published in peer reviewed journals, magazines and books. The scientific explanations have been oversimplified, as per my style, with an eye to connect to readers from all walks of life. It is advisable to take things presented here as a light, rough and ‘moderately’ scientific guide to what is happening in the scientific world today. Here is a list of references for interested individuals who want to plunge deeper into the field. Good luck.
(1) W. Barthlott et al. Planta, 1997, volume 202, page 1
(2) A. Tuteja et al. Science, 2007, volume 318, page 1618
(3) A. K. Geim et al. Nature materials, 2003, page 461, volume 2
(4) A. Nakajima et al. Langmuir, 2000, volume 16, page 7044
(5) The Gecko’s foot. Bio-inspiration: Engineered from nature, by Peter Forbes, 4th edition.
(6) Lizard helps adhesive design, Helen R. Pilcher, nature news 2nd June 2003