NASA Goddard Space Flight Center has developed a printable nanosensor and leads using 3D printing techniques on a silicon daughter board that can be connected to a self-contained pre-amp printed circuit board (PCB). The sensor contains a graphene sensor array (a printed CNT or MoS2 could also work) and a PCB with pre-amplifier circuit connected to the daughter board with mechanical clips and wire-bonded together. The sensor dimensions are typically from microns to hundreds of microns. This innovation increases the sensitivity of gas sensors, enabling detection of ppb level concentration (and possibly single molecules).

The sensors use field effect transistors based on two-dimensional materials to sense the surface potential of a graphene channel exposed to an analyte. When analyte molecules adsorb onto the sensor surface, they act as electron donors or acceptors, inducing a local change in electrical resistance in graphene. This effect is very pronounced in 2D materials due to high surface area, high electrical conductivity (in the case of graphene), and inherent low noise, making it possible to detect the changes in resistance.

Different gases have different effects on the resistivity. The selectivity among target gases can be improved further through functionalization of the 2D materials. The sensors are microfabricated on a suitable substrate as arrays. Different sensors on the array can have different functional groups targeting different analytes.

NASA is actively seeking licensees to commercialize this technology. For more information, please contact NASA’s Licensing Concierge at Agency-Patent-Licensing@mail. nasa.gov or call us at 202-358-7432 to initiate licensing discussions.


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This article first appeared in the February, 2021 issue of Tech Briefs Magazine.

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