Researchers from Penn State University, along with researchers from Northeastern University, have announced that they have developed a highly sensitive, wearable gas sensor for environmental and human health monitoring. The researchers believe that the wearable sensor may soon become commercially available. The new sensor is an improvement on existing wearable sensors thanks to its self-heating mechanism that enhances sensitivity.
The self-heating mechanism allows for quick recovery and reuse of the wearable sensor. The researchers note that other devices of this type require an external heater, and require expensive and time-consuming lithography process under cleanroom conditions for production. Scientists on the project used a laser to pattern a highly porous single line of nanomaterial said to be similar to graphene.
The material was used to create sensors that can detect gas, biomolecules, and in the future will be able to detect chemicals. The non-sensing portion of the device uses a series of serpentine lines that are coated with silver. Applying an electrical current to the silver locally heats up the gas sensing region of the sensor, eliminating the need for a separate heater. The serpentine lines allow the wearable sensor to stretch, like Springs, to adjust to the flexing of the body.
That capability is critical to wearable sensors. Nanomaterials used in this application are reduced graphene oxide and molybdenum disulfide, or combination of the two. The materials could also use a metal oxide composite featuring a core of zinc oxide and a shell of copper oxide.
The scientists say that the US Defense Threat Reduction Agency is interested in the wearable sensor to detect chemical and biological agents that could damage the nerves or lungs. A medical device company is also working with the team to scale production for patient health monitoring, including gaseous biomarker detection in the human body and environmental detection of pollutants that can affect the lungs. The team is currently working on creating high-density arrays and improving the signal to make the sensors more selective.