An electronic clone of biological skin that stands to enrich biological, virtual, and robotic life.
What it is
Electronic skin (E-skin) mimics the aesthetics and simulations of natural biological skin.1 Made of multiple layers of thin, soft, flexible materials 2 with embedded sensors, 3 it can be applied to people,4 animals, amputated limbs, and robots to provide a degree of feeling, whether as a ‘second skin’, or in replacement of an area of biological skin.5 There are many types of E-skin, and various ways to develop them. Many are able to heal.6 It is not yet available commercially.
How it works
Attached as a self-adhesive patch, 7 operating with minimal user awareness 8 and energy- autonomously,9 E-skin employs hundreds of sensors to measure multiple signals in its immediate environment. These can be:
- Ambient parameters from the immediate environment e.g. temperature, humidity, oxygen and carbon dioxide levels, salinity etc. and/or mechanical stimuli such as pressure.10
- Biophysical parameters of the user e.g. changes in body temperature, pressure (touch), electrical signals of the heart, and respiratory rhythm.11 12 Some E-skins monitor the body’s movement and motions using magnetic-field sensors.13
Data are fed back wirelessly, in real time, usually through a single receiver acting as one system,14 using e.g. a mobile application. Functionality is maintained even if some receptors are damaged.15
For prosthetics, 16 biomimetic signals are made intelligible to a user’s nervous system by transmitting digital signals from the sensors to the brain through nerve tissues, allowing the body to respond appropriately.17 Signals to and from the nervous system,18 including touch,19 are 1,000 times faster than with natural skin.
For robotics, data stored by and retrieved from the E-skin, and sent to a controller in a closed-loop feedback, makes it possible to control the movement of the robot in real time.20
Personal healthcare monitoring. Measuring body temperature and or chemical and electrophysiological changes in real time for increased accuracy, and earlier diagnosis of health problems such as epilepsy, sleep disorders, heart disease, and skin hydration.21
Marine life. ‘Marine-skin’ monitors behaviour, water temperature, pressure and salinity, aiding the study of marine ecosystems, which are facing unprecedented change due to global warming.22
Human-Machine interaction. Enabling non-verbal communication between robots and humans – the robot can be slapped to discourage bad behaviour or tickled for positive feedback.23
Prosthetics. Restoring sensations 24 to amputees, 25 including pain; improved reliability and longevity of unit.26
Robotics. Facilitating currently-challenging functions such as: dexterity,27 and search-and-rescue.28
Virtual and Augmented Reality, and gaming. The body’s angular position and movement interact with virtual characters and objects that react appropriately to changes in the user’s movement.29
Security, telecommunication. Removing vibrational distortions30 enables vocal identification.
Implications and issues
People. Accurate, continuous, and personalised healthcare diagnostics;31 improved quality of life, and opening up of greater work and leisure opportunities for amputees; bioethics; changing attitudes towards disability; implications for transhumanism32 when e-skin becomes ‘superior’ to biological skin.33 Greater levels of interaction and levels of emotional connection in the gaming and virtual world; bridging of the virtual and real world, potentially transforming the gaming industry.34 Animals and marine life. Improved ecology and conservation.
Robots will become more ‘human’, while humans will become more ‘robotic’, facilitation of self- sufficient robots. Implications for sex industry will presumably be significant.
Privacy. As with all digital technologies, it has big policy and data ownership implications.35◼
1 Scientificeuropean.co.uk. (2018). ‘e-Skin’ That Mimics The Biological Skin and Its Functions. [online] Available at: https://www.scientificeuropean.co.uk/e-skin-that-mimics-the-biological-skin-and-its-functions [Accessed 27 Jan. 2020].
2 Chortos, A., Liu, J. and Bao, Z. (2016). Pursuing prosthetic electronic skin. Nature Materials, 15(9), pp.937-950. https://doi.org/10.1038/s41528-018-0045-x
3 Seminara, L., Pinna, L., Ibrahim, A., Noli, L., Capurro, M., Caviglia, S., Gastaldo, P. and Valle, M. (2014). Electronic Skin: Achievements, Issues and Trends. Procedia Technology, 15, pp.549-558. doi: 10.1016/j.protcy.2014.09.015
4 Oh, J. and Bao, Z. (2019). Second Skin Enabled by Advanced Electronics. Advanced Science, p.1900186. https://doi.org/10.1002/advs.201900186
5 E-skin can restore sensations to people with skin damage. The paper below compares how the artificial skin receptors are transduced in comparison to biological skin transduction.
See: Chortos, A., Liu, J. and Bao, Z., 2016. Pursuing prosthetic electronic skin. Nature Materials, 15(9), pp.937-950.
6 The healing feature imitates the wound-healing capability of natural skin. It makes the E-skin more reliable, durable, which are important cost considerations for amputees when deciding to purchase prosthetic devices. With modest, mechanical damage,
the e-skin can be re-healed by applying heat with a re-healing agent. More recent research focuses on autonomous self-healing. If the damage is acute, the e-skin can be completely recycled, leaving no waste, satisfying the environmental considerations of producing e-skins.
For more on the methods see:
Zou, Z., Zhu, C., Li, Y., Lei, X., Zhang, W. and Xiao, J. (2018). Rehealable, fully recyclable, and malleable electronic skin enabled by dynamic covalent thermoset nanocomposite. Science Advances, 4(2), p.eaaq0508. DOI: 10.1126/sciadv.aaq0508
7 These patches attach using strongly-adhesive electrodes. Yang, J., Mun, J., Kwon, S., Park, S., Bao, Z. and Park, S. (2019). Electronic Skin: Recent Progress and Future Prospects for Skin‐Attachable Devices for Health Monitoring, Robotics, and Prosthetics. Advanced Materials, 31(48), p.1904765.
8 ScienceDaily. (2017). Electronic skin’ takes wearable health monitors to the next level: A soft, stick-on patch collects, analyzes and wirelessly transmits a variety of health metrics from the body to a smartphone. [online] Available at: https://www.sciencedaily.com/releases/2017/08/170821094309.htm [Accessed 28 Jan. 2020].
9 One possible implication of the energy autonomy of E-skin is that it may not be able to be turned off.
García Núñez, C., Manjakkal, L. and Dahiya, R. (2019). Energy autonomous electronic skin. npj Flexible Electronics, 3(1). https://doi.org/10.1038/s41528-018-0045-x
10 Li, S., Zhang, Y., Wang, Y., Xia, K., Yin, Z., Wang, H., Zhang, M., Liang, X., Lu, H., Zhu, M., Wang, H., Shen, X. and Zhang, Y. (2019).
Physical sensors for skin‐inspired electronics. InfoMat, 2(1), pp.184-211.
11 Xu, K., Lu, Y. and Takei, K. (2019). Multifunctional Skin-Inspired Flexible Sensor Systems for Wearable Electronics. Advanced Materials Technologies, 4(3), p.1800628. DOI: 10.1002/admt.201800628
12 García Núñez, C., Manjakkal, L. and Dahiya, R. (2019). Energy autonomous electronic skin. npj Flexible Electronics, 3(1). https://doi.org/10.1038/s41528-018-0045-x
13 Cañón Bermúdez, G., Karnaushenko, D., Karnaushenko, D., Lebanov, A., Bischoff, L., Kaltenbrunner, M., Fassbender, J., Schmidt,
O. and Makarov, D. (2018). Magnetosensitive e-skins with directional perception for augmented reality. Science Advances, 4(1), p.eaao2623. doi: 10.1126/sciadv.aao2623 https://doi.org/10.1002/adma.201904765
14 According to this study, although 240 sensors were integrated on a single system, it could potentially be scaled up to 10,000 without compromising its performance.
For more on how it works, see: Lee, W., Tan, Y., Yao, H., Li, S., See, H., Hon, M., Ng, K., Xiong, B., Ho, J. and Tee, B. (2019). A neuro- inspired artificial peripheral nervous system for scalable electronic skins. Science Robotics, 4(32), p.eaax2198. DOI: 10.1126/scirobotics.aax2198 and Scully, R. (2019). Artificial skin can sense 1000 times faster than human nerves. [online] New Scientist. Available at: https://www.newscientist.com/article/2210293-artificial-skin-can-sense-1000-times-faster-than-human- nerves/ [Accessed 13 Feb. 2020].
15 Jee, C. (2019). A sensor-filled “skin” could give prosthetic hands a better sense of touch. [online] MIT Technology Review. Available at: touch/ [Accessed 14 Feb. 2020].
16 Yang, J., Mun, J., Kwon, S., Park, S., Bao, Z. and Park, S. (2019). Electronic Skin: Recent Progress and Future Prospects for Skin‐ Attachable Devices for Health Monitoring, Robotics, and Prosthetics. Advanced Materials, 31(48), p.1904765. Available from: doi.org/10.1002/adma.201904765
17 Biomimetic signals imitate biochemical processes. Receptors convert the external stimuli into electrical signals which are then transmitted to the nerves and to the brain.
For more, see: Chortos, A., Liu, J. and Bao, Z. (2016). Pursuing prosthetic electronic skin. Nature Materials, 15(9), pp.937-950. DOI: 10.1038/NMAT4671, and Li, S., Zhang, Y., Wang, Y., Xia, K., Yin, Z., Wang, H., Zhang, M., Liang, X., Lu, H., Zhu, M., Wang, H., Shen,
X. and Zhang, Y. (2019). Physical sensors for skin‐inspired electronics. InfoMat, 2(1), pp.184-211. DOI: 10.1002/inf2.12060
18 Scully, R. (2019). Artificial skin can sense 1000 times faster than human nerves. [online] New Scientist. Available at: https://www.newscientist.com/article/2210293-artificial-skin-can-sense-1000-times-faster-than-human-nerves/ [Accessed 13 Feb. 2020].
19 Begum, S. (2019). Prosthetics can sense touch with ‘electronic skin’ invention. [online] The Straits Times. Available at: https://www.straitstimes.com/singapore/prosthetics-can-sense-touch-with-electronic-skin-invention [Accessed 30 Jan. 2020].
20 Boutry, C., Negre, M., Jorda, M., Vardoulis, O., Chortos, A., Khatib, O. and Bao, Z. (2018). A hierarchically patterned, bioinspired e-skin able to detect the direction of applied pressure for robotics. Science Robotics, 3(24), p.eaau6914.
21 Changes in body temperature is a meaningful health indicator of many medical diagnosis. Rather than measuring changes in the traditional, periodic way using thermometers. Realtime analysis help medics to find unusual changes in condition more accurately and in advance.
For more, see Xu, K., Lu, Y. and Takei, K. (2019). Multifunctional Skin-Inspired Flexible Sensor Systems for Wearable Electronics.
Advanced Materials Technologies, 4(3), p.1800628. DOI: 10.1002/admt.201800628
22 The behaviour of captured marine animals, their environmental conditions, and geographical location can be monitored by attaching e-skin on to their natural skin. Data on the animal’s temperature, water salinity, and potentially oxygen and carbon dioxide levels of the animal’s environment can be recorded in real-time when released. Once recaptured, the data can be
collected and recorded. The ‘Marine Skin’ can be used as a tracking device for aquatic animals.
For more, see Nassar, J., Khan, S., Velling, S., Diaz-Gaxiola, A., Shaikh, S., Geraldi, N., Torres Sevilla, G., Duarte, C. and Hussain, M. (2018). Compliant lightweight non-invasive standalone “Marine Skin” tagging system. npj Flexible Electronics, 2(1). https://doi.org/10.1038/s41528-018-0025-1
and Coxworth, B. (2019). Animal-adhered data patch gets smaller and better. [online] New Atlas. Available at: https://newatlas.com/marine-skin-smaller-deeper/59385/ [Accessed 25 Feb. 2020], and Hsu, J. (2018). Full Page Reload. [online] IEEE Spectrum: Technology, Engineering, and Science News. Available at: https://spectrum.ieee.org/tech-talk/green- tech/conservation/marine-skin-wearable-tracks-animals-under-the-sea [Accessed 25 Feb. 2020].
23 Yogeswaran, N., Dang, W., Navaraj, W., Shakthivel, D., Khan, S., Polat, E., Gupta, S., Heidari, H., Kaboli, M., Lorenzelli, L., Cheng,
G. and Dahiya, R. (2015). New materials and advances in making electronic skin for interactive robots. Advanced Robotics, 29(21), pp.1359-1373. https://doi.org/10.1080/01691864.2015.1095653
24 The e-skin acts as a skin-like covering to the prosthetic, enabling pain reflex as well as the ability to gather important information about the environment, preventing damage to the prosthetic.
25 In the UK, the government currently has a budget of £11 million for military amputees. Countries that offer universal health coverage may face issues around equality, and access to e-skins. See: commissioning, N., 2020. NHS Commissioning » Veterans’ Prosthetics. [online] England.nhs.uk. Available at: <https://www.england.nhs.uk/commissioning/armed-forces/veterans- prosthetics/> [Accessed 10 March 2020].
26 Osborn, L., Dragomir, A., Betthauser, J., Hunt, C., Nguyen, H., Kaliki, R. and Thakor, N. (2018). Prosthesis with neuromorphic multilayered e-dermis perceives touch and pain. Science Robotics, 3(19), p.eaat3818.
27 Robots that are capable of grasping, and manipulating delicate objects such as soft fruit without damage; as well as ones that are able to assess sensitivity of the objects with which they are interacting.
Knight, H. (2019). Electronic skin gives robots the human touch . The Engineer. [online] The Engineer. Available at: https://www.theengineer.co.uk/electronic-skin-gives-robots-the-human-touch/ [Accessed 3 Feb. 2020].
28 Begum, S. (2019). Prosthetics can sense touch with ‘electronic skin’ invention. [online] The Straits Times. Available at: https://www.straitstimes.com/singapore/prosthetics-can-sense-touch-with-electronic-skin-invention [Accessed 3 Feb. 2020].
29 E-skins with directional perception and body position tracking enable the user as well as the virtual characters to interact and respond to body movement, making supplemented reality more real.
Cañón Bermúdez, G., Karnaushenko, D., Karnaushenko, D., Lebanov, A., Bischoff, L., Kaltenbrunner, M., Fassbender, J., Schmidt,
O. and Makarov, D., 2018. Magnetosensitive e-skins with directional perception for augmented reality. Science Advances, 4(1), p.eaao2623.
30 The e-skin records detect changes in the skin’s vibrations rather than sound pressure. For more, see Lee, S., Kim, J., Yun, I., Bae, G., Kim, D., Park, S., Yi, I., Moon, W., Chung, Y. and Cho, K. (2019). An ultrathin conformable vibration-responsive electronic skin for quantitative vocal recognition. Nature Communications, 10(1). https://doi.org/10.1038/s41467-019-10465-w
31 Live monitoring has significant importance because it replaces the traditional way of recording health conditions periodically. See: Yang, J., Mun, J., Kwon, S., Park, S., Bao, Z. and Park, S. (2019). Electronic Skin: Recent Progress and Future Prospects for Skin‐ Attachable Devices for Health Monitoring, Robotics, and Prosthetics. Advanced Materials, 31(48), p.1904765.
32 Transhumanism is a philosophical movement or belief that human intellect and physiology can evolve by means of emerging technologies.
33 For more, see Xu, K., Lu, Y. and Takei, K. (2019). Multifunctional Skin-Inspired Flexible Sensor Systems for Wearable Electronics.
Advanced Materials Technologies, 4(3), p.1800628. DOI: 10.1002/admt.201800628. Some E-skin can ‘smell’ an object through
with contact. See Colman, J. (2019). This skin will make robots more human. [online] Red Bull. Available at: https://www.redbull.com/gb-en/wootzkin-skin-interview [Accessed 19 Feb. 2020].
34 According to Forbes, the gaming industry generated some $138.7 bn in revenue in 2019. The introduction of VR has already opened up new businesses such as Virtual Reality arcades. E-skin could further transform the entertainment industry by opening up a new cyber-enabled setting for gaming, social networking and interaction.
Anderton, K., 2019. The Business Of Video Games: Market Share For Gaming Platforms In 2019. [online] Forbes. Available at:
<https://www.forbes.com/sites/kevinanderton/2019/06/26/the-business-of-video-games-market-share-for-gaming-platforms-in- 2019-infographic/#39599c6c7b25> [Accessed 10 March 2020].
35 For example, competence of people with physical disabilities using bionic technologies will need to be reassessed to comply with Equality Acts.