NASA has patented a unique chemical sensor array leveraging nanostructures for monitoring the concentration of chemical species or gas molecules that is not damaged when exposed to protons and other high-energy particles over time. The nanotechnology-enabled chemical sensor array uses single walled carbon nanotubes (SWCNTs), metal catalyst-doped SWCNTs, and polymer- coated SWCNTs as the sensing media between a pair of interdigitated electrodes (IDE). By measuring the conductivity change of the SWCNT device, the concentration of the chemical species or gas molecules can be measured. These sensors have high sensitivity, low power requirements, and are robust and have a low manufacturing cost compared to other commercial chemical sensors for detection of trace amount of chemicals in gasses and liquids.
Carbon nanotube chemical sensors are suitable for sensing different analytes. Such sensors can be configured in the form of an array to comprehensively and cost-effectively monitor multiple analytes. A 32-sensor array on a silicon chip was tested under proton exposure at two energy levels, with three different fluences. The result of the proton irradiation experiment indicates that this SWCNT device is sensitive to proton exposure at different levels, and it recovers upon turning off the incident radiation. Carbon nanotube-based sensors are particularly suitable and promising for chemical and radiation detection, because the technology can be used to fabricate gas or liquid chemical sensors that have extremely low power requirements and are versatile and ultra-miniature in size, with added cost benefits. Low-power carbon nanotube sensors facilitate distributed or wireless gas sensing, leading to efficient multi-point measurements and to greater convenience and flexibility in performing measurements in space as well as on Earth.
The technology offers tunable sensing properties through manipulation of nanostructured materials for selectivity, and gives reliable sensor performance from chip to chip. It has the capability to put built-in intelligence onto the sensor chip.
The sensor array’s low power consumption makes it ideal for wireless monitoring. This sensor technology can be used in the petrochemical industry, the nuclear industry, industrial and civil applications, defense applications, medical/ biomedical designs, and spacecraft.