The Amazing Gecko
The focus of the amateur blog post series so far has largely been on the human body in health and disease. However, the structure and function of other living organisms are equally fascinating. Delivering my public engagement workshop on bio-inspired technologies at an outstanding academy in North London yesterday reminded me of the endless outcomes science can engender. Humans continuously turn to God’s creations to gain incentive for new technologies, hence the term ‘bio-inspired'. The gecko is just one from a countless number of sources of inspiration from nature.
Being renown for its ability to climb vertical surfaces, the gecko is a unique class of reptile which differs from the common lizard by its extraordinary foot structure. The immaculate design of the gecko toe is what underlies its ability to adhere to vertical surfaces including glass and ceilings. It has much broader, bigger toes compared to lizards which increase the surface area in contact with the surface being climbed. For over 200 years, scientists have been exploring the reasons why geckos can climb walls but lizards and humans cannot. The gecko foot was visualised in nano-scale following the discovery of the electron microscope in the 1950s, highlighting some captivating detail.
Observing the structure in more depth, one can see that there are millions of hairs on each foot, and each single strand of hair has hundreds of smaller spatula-like 'nano'-hairs on the end which maximise the branches of hair touching the surface. Spatula-shaped fine hairs exert attractive van der Waals' forces between their β-keratin and the surface being climbed. Also known as intermolecular forces, these are the weakest of the various chemical bonds that can exist between two different molecules. Nonetheless, these small-scale forces add up to a collective force powerful enough to allow the gecko to carry objects that are twenty times heavier than itself. Thus, geckos can make contact with up to 50% of the surface they want to climb, whereas the bumpy structure of the human hand means that we only make physical contact with 0.01% of any target surface.
When considering the fact that one nanometre equals to one billionth of a metre, that each hair has a hundred of these nano-hairs on its end, and that there are approximately three million long hairs on each foot, it is difficult not to be awe-struck by the intricacy of the gecko foot's design. What an immaculate Designer! Traces of His divine wisdom can be seen in all His creations: "And on the Earth are signs for the certain (in faith) and in yourselves. Then will you not see?" (al-Dhariyat 51:20-21) and the nanostructure of the foot of this tiny lizard is just one of these traces. There is no doubt that discovering and pondering over the signs readily available in all living beings around us- no matter how big or small- point to the Creator's Presence, Oneness, and Authority. The marvellous bodies that follow regular laws of motion on Earth have all been created in such perfect proportion and measure that we can do little but appreciate God's supreme artistry.
Hoping to spark some deeper questions in the minds of the curious cohort of young, bright pupils at the workshop, I explored how mimicking the gecko hand has allowed us to design new technologies for the wider benefit of society. From the most basic example of the adhesive gecko pad for usage in cars to use of gecko-technology on car tyres to improve grip on slippery roads, to gecko-inspired bandages to eliminate the need to do sutures to close up wounds, to the gecko robots designed in Stamford university to use for cleaning the windows of tall buildings, emergency services and surveillance cameras, attendees listened to the possibilities of real-life use of gecko-inspired technology with interest. Although man-made products are far from the perfection of the gecko foot, transforming the gecko gloves Tom Cruise uses to climb the Burj Khalifa to complete his Mission Impossible (IV) might be possible one day after all!
