Graphene-based sensors could be used to monitor adverse environments that are inhospitable to present-day technologies.
Graphene is an intriguing form of carbon, containing layers of interconnected hexagonal rings of carbon atoms. This structure has special physical and electronic properties with potential for several applications.
Graphene has been projected as a miracle material for years now, but its application in harsh environmental conditions was unexplored. Existing sensor technologies operate in a very limited range of environmental conditions, failing or becoming unreliable if there is much deviation.
Sohail Shaikh, King Abdullah University of Science and Technology
Shaikh has designed the novel sensors in collaboration with Muhammad Hussain from King Abdullah University of Science and Technology (KAUST).
The new, powerful sensor depends on variations in the electrical resistance of graphene in response to acidity, fluctuating temperatures, and salinity of a solution quantified as pH. The system has the ability to track extra variables, such as pressure and water flow rates.
The team pointed out that sensing for numerous variables can be integrated into a solo device, significantly boosting its utility.
The graphene is placed on a flexible sheet of polyimide polymer, and it can be linked to suitable electronic systems to gather and convey the signals for whichever environmental variable is being tracked. Then, with the help of standard Bluetooth technology, the resultant information could be sent wirelessly.
System resilience is the greatest practical advance. This resilience enables the system to endure temperatures as high as 650 °C and also tolerate powerful radiation, varying pressure, high salinity, high humidity, reactive chemicals, or any combination of these conditions.
In addition, the sensors can provide benefits in terms of sensitivity—for instance, it achieves an increased sensitivity of 260% in temperature sensing in relation to an existing alternative.
Our study is the first to show decisively the prospects of graphene as a sensing material for a variety of harsh environmental conditions.
Muhammad Hussain, King Abdullah University of Science and Technology
Potential real-world applications include tracking conditions in body fluids, ocean water, space exploration, the oil and gas sector, and several situations that involve exposure to chemicals that would destroy the existing sensors.
The thin structure and flexibility of the new sensor also make it appropriate for use in wearable technologies for athletes and divers, or in medical applications.
According to the team, continual developments that connect electronic devices with the Internet of Everything (IoE) and the Internet of Things (IoT) technologies will bring several needs and opportunities for their strong and flexible sensors.
Shaikh, S F & Hussain, M M (2020) Multisensory graphene-skin for harsh-environment applications. Applied Physics Letters. doi.org/10.1063/5.0017769.