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Scientists in Barcelona, Spain, have developed a new breed of wearable light sensors based on graphene. These sensors use ambient light to accurately measure vitals such as human pulse and blood oxygen levels. Their innovation has implications for the future of health-care monitoring, offering the sector augmented wearables that could be used to monitor and prevent healthcare issues.
Current Wearables Use Rigid Sensors That Limit Effectiveness
Wearable technology has become increasingly popular in recent years. The US market is predicted to be valued at $51.6 billion by 2022, representing a rapid growth at a CAGR of 15.51% from 2016 to 2022. Devices are being used to benefit the health of wearers by monitoring their vitals, helping them to track and improve their fitness levels, as well as to prevent them from developing common health problems such as hypertension, heart failure, stress-related complications, and more.
While current wearables available on the market may have a soft outer shell, they are constructed by rigid sensors and electronics, which prevents them from being as efficient and accurate as they could be because the sensors are not in optimum contact with the skin.
The Spanish team set to overcome this drawback by developing a sensor that is completely flexible and transparent to allow it to collect more accurate measurements of vitals. To achieve this they developed a system that uses ambient light that is detected by an innovative sensor constructed of graphene, covered with a layer of semiconducting nanoparticles to measure these vital signs.
Developers of the next generation of wearable devices are heavily focused on exploring how 2D materials can be used to augment the designs of current technologies. 2D materials have many features that appeal to the development of enhanced wearables, such as electrical conductivity, optical transparency, mechanical flexibility, biocompatibility, and stability to biological electrolytes. Graphene is one such example of a 2D material, and it has already been used successfully to create tattoo-like devices that can measure a number of vitals with impressive accuracy.
The Development of An Improved Device
A recent study, published in the journal Science Advances, outlines how researchers created a revolutionary flexible and transparent wearable device capable of delivering continuous and accurate measurements of vital signs such as respiration rate, heart rate, blood pulse oxygenation, and exposure to UV radiation. The benefits of the device are that its read-out is produced on a connected device, and can operate battery-free by charging it wirelessly through a phone.
In addition, the bracelet is designed to adapt to the skin surface, enabling optimized contact for continuous measurement. It incorporates a light sensor that is also flexible and can use light information to determine changes in the volume of blood vessels due to the cardiac cycle and calculate vitals from this information. Also, the researchers developed a graphene health patch that can be adhered to the screen of a mobile phone to give real-time measurements from the touch of a finger.
The most unique feature of the design is that it uses ambient light to collect measurements, enabling a device that consumes little energy and promotes continuous monitoring of health markers. Using this core technology, a flexible UV patch prototype was also constructed which also operates battery-free and can collect continuous, reliable data, to be used to alert wearers to the danger of over-exposure.
Implications For the Future of Healthcare
What was achieved by the team in Barcelona is likely to have a game-changing effect on the landscape of wearable technology. The use of graphene-quantum-dots in fully flexible wearable devices has been demonstrated to be successful, and the opportunity is now there to develop commercially ready wearable devices based on this technology that may allow for the establishment of improved health-monitoring wearables.