Also, human skin is an asset which is highly esteemed and that is why attention is given to the care of the skin.
The skin gives a lot of information about a man, for instance the skin tells so much about the health status of a man, high temperature can be felt by mere touching the skin with elevated body temperature, with that, we know that a great deal is going on inside the man. Thanks to the nerves endings that is doing a great job in ensuring that information received from the body periphery is passed to the brain. If our nerve ending is not functional, we might definitely not have any sensation. Thanks to free nerve ending that help us to respond to external stimuli.
Anyway, human skin is a great asset which is not only there to let us have the feel of our immediate environment but to also communicate. Even when your mouth can hardly express your feelings or tell who you are, your skin can do the talking without any confusion.
In this era of advance technology when solution to human need is gaining top priority in the world of science, discoveries has been made on how human skin can be an asset to solve his needs or even to be an aid to help human solve his own health challenges.
To this end, there has been advance studies in the development and use of electronic skin which involves the use of electronics to imitate skin sensory ability. This technology when fully developed to its optimum capacity, its application in artificial intelligence, robotic science, digital health, human-machine interaction and internet of
thing can not be brush aside.
Since human skin is flexible and has nerve ending, anything that will give similar function should have same feature. So for electronic skin to provide tactile sensing, it will have to be flexible, and possess pressure stretchable sensors arrangement which are structurally designed based on different mechanism of information transfer.
These arrangement similar to nerve ending with high resolution can
provide pressure with rapid response far more than human could respond to stimuli. So with electronic skin, temperature detection, humidity sensation, and multi-modal-force sensing interface and many more can be easily explored, and provide possible solution to human health and other challenges.
The electronic skin for easy mobility is always light weight. The e-skin is not just a piece of nylon or folded material,but it contain several electronic components such as actuator, sensors and other electronic component which needs to be powered for it to function efficiently.
Need for autonomous energy source
It will be difficult if you wear an electronic skin perhaps for digital health purpose to monitor heart rate, only for you to find out that the power is down and the battery needs to be changed, or you need to charge it. Such may spell doom for the wearer. So there is a need for self powered electronic skin. The kind that will provide energy that it needs.
Principle of operation of self powered e-skin
For a self powered electronic skin to function efficiently, it should be able to harvest energy enough for it to function properly from its own environment. As it contains lot of sensors and other electronic component. It should be autonomous such that no need to depend on external energy source, it should also be able to perform biosensing , gathered both physical and molecular information and send gathered data through bluetooth communication system. Such is the one that uses sweat from our skin as its own energy.
Sweat as power source
What could make sweat from our skin powered an electronic device implanted on the skin?.
First of all, we produce sweat when the temperature of our body goes beyond 37°C or 98.6°F. Our skin produces sweat when our skin gland is stimulated by nervous system to cool down the body temperature. In other word, sweat plays a great role in thermoregulation of human body. Sweat not only play thermoregulatory role in the skin, it also help human for homeostatic function such as removal of waste a function which is identical with renal system responsible for removing excess micronutrients, metabolic waste and other toxicant in the body.
An example of such waste removed from the body through sweat is a compound known as lactate.
Lactate is the fuel feed
Lactate is a waste produced in the muscles cells during anaerobic metabolism. During exercise, shortest way by which body get energy is through anaerobic metabolism which involves breaking down of glucose ( a six carbon sugar) to two pyruvate(a three carbon compund) in the absence of oxygen , although aerobic metabolism is the main process of how energy is made availabe to the body cells in the presence of oxygen. During aerobic metabolism, 39 ATP (fuel for the cells) is produced but with anaerobic metabolism, only 3ATP is produced and there we have lactic acid as waste product with the aid of enzyme lactate dehydrogenase (LDH).
Lactate accumulation is dangerous to the body,but it increases during physical exercise. So in the homeostatic function of the skin, lactate is eliminated. Though not primarily by the skin but much more by the liver and the kidney. The lactate eliminated by the skin can be harvested by the fuel cells incorporated into the e-skin, combine it with atmospheric oxygen and then produces water and pyruvate. As this operation proceeds, the incorporated fuel cells generates electricity sufficient enough to power the sensors as well as Bluetooth device in the e-skin for the onward transmission of data from the sensor. In this way, physiological signal is monitored by the electronic skin.
Apart from the fuel compartment that convert the chemical lactate to electricity, the biosensors of the e-skin can also process metabolic data glucose, urea and pH levels which can be used to monitor certain ailments such as diabetes, ischemia, elevated body temperature and others.
The novel about the electronic-skin is that the fuel cells electrode are uniquely designed from nanomaterials. The cathode is made of carbon nanotube(diameter measured in diameter) garnished with alloy of platinum and cobalt in nanoparticles size, while the anode is made of nanocomposite material that incorporates the enzyme which breaks down the lactate. The fuels cells as long as there is sweat can spawn steadily power for several days.
Conclusion
Wearing an electronic skin over our skin can go a long way to quickly detect life threatening diseases.We should not also be surprised if in the near future we just have to watch movie, make and receive calls from our skin embedded with wearable devices.
References
Energy autonomous electronic skin
Electronic poweredowerd by sweat
Electronic skin fitted with disco light
Recent progress in Electronic skin