Electronic tattoos

[Dutch Uncle]

Tech is always improving. One area is wearable body sensors injected into the skin. Anyone who wears tech like a Fitbit/Amazfit can see the advantages of one that doesn't need recharging, can't be lost and is completely out of the way.

Other advantages will be tracking pets and kids...or spouses. LOL

FWIW, I'd get one. I wear an Amazfit band, the spouse and I share cellphone locations and use Apple Airtags.

https://pubs.acs.org/doi/10.1021/acsnano.7b02182

Tattoo-like epidermal sensors are an emerging class of truly wearable electronics, owing to their thinness and softness. While most of them are based on thin metal films, a silicon membrane, or nanoparticle-based printable inks, we report sub-micrometer thick, multimodal electronic tattoo sensors that are made of graphene. The graphene electronic tattoo (GET) is designed as filamentary serpentines and fabricated by a cost- and time-effective “wet transfer, dry patterning” method. It has a total thickness of 463 ± 30 nm, an optical transparency of ∼85%, and a stretchability of more than 40%. The GET can be directly laminated on human skin just like a temporary tattoo and can fully conform to the microscopic morphology of the surface of skin via just van der Waals forces. The open-mesh structure of the GET makes it breathable and its stiffness negligible. A bare GET is able to stay attached to skin for several hours without fracture or delamination. With liquid bandage coverage, a GET may stay functional on the skin for up to several days. As a dry electrode, GET–skin interface impedance is on par with medically used silver/silver-chloride (Ag/AgCl) gel electrodes, while offering superior comfort, mobility, and reliability. GET has been successfully applied to measure electrocardiogram (ECG), electromyogram (EMG), electroencephalogram (EEG), skin temperature, and skin hydration.

https://dst.gov.in/tattoo-sensor-monitoring-vital-health-parameters

Active research in the field of epidermal electronics has spawned an important class of wearable sensors that aim to deliver point of care diagnostics with comfortable and robust user experience. Conventional medical devices are bulky, rigid, and non-practical because they do not allow continuous monitoring of vital health parameters while continuing day to day life schedule. The soft and curvilinear shape of human body needs skin like sensors that can be tattooed on the body with an easy transfer process.

Dr. Saurabh Kumar from Centre for Nanoscience and Engineering (CeNSE) at Indian Institute of Science, Bangalore, India, a recipient of the INSPIRE Faculty Fellowship instituted by the Department of Science & Technology, Govt. of India is currently working on wearable sensors that can retract information from human body using its largest organ, the skin.

In his recent work published in the journal ‘ACS Sensors’, his group has fabricated a skin conformal tattoo sensor about 20 μm thick. The sensor promises inconspicuous and continuous monitoring of vital health parameters of an individual, like pulse rate, respiration rate, and surface electromyography. The sensor serves as a single conduit for sensing respiration rate and pulse, dispensing with the need of mounting multiple sensors. Its remarkably high sensitivity with a gauge factor (GF) has been ascribed to the development of nano-cracks and their propagation through the film upon application of strain. The fast response and highly repeatable sensor follows easy fabrication steps and can be patterned into any shape and size using a laser.

The Skin conformal sensor has the ability to perform non-invasive and continuous monitoring of vital health parameters. Further, it has the potential to replace rigid and bulky health monitoring devices.

These sensors do not interfere with the daily activities of the user, thus enabling continuous monitoring of vital signs like pulse rate, respiration rate, UV rays exposure, skin hydration level, glucose monitoring, and so on.

Apart from pursuing his research on sensors, Dr. Kumar is also training students in cutting-edge research in biosensor technologies while actively engaging them in the development of tools for bio-research and clinical diagnosis.

https://pubs.acs.org/doi/10.1021/acssensors.0c00647

The discovery of stable two-dimensional (2D) materials has effectuated a rapid evolution of skin conformal sensors for health monitoring via epidermal electronics. Among the newly discovered 2D materials, MXene stands out as a solution-processable 2D material allowing easy fabrication of highly conductive thin films with the potential to realize flexible skin conformal sensors. Here, we present a successful demonstration of a Ti3C2–MXene resistor as an extremely sensitive strain sensor in the form an ultrathin skin mountable temporary tattoo. The skin conformability and form factor afforded by the sensor promises inconspicuous and continuous monitoring of vital health parameters of an individual, like the pulse rate, respiration rate, and surface electromyography. The sensor serves as a single conduit for sensing the respiration rate and pulse, dispensing with the need of mounting multiple sensors. Its remarkably high sensitivity with a gauge factor of ∼7400 has been ascribed to development of nanocracks and their propagation through the film upon application of strain. The fast response and highly repeatable sensor follows easy fabrication steps and can be patterned into any shape and size using a laser.