Advanced Functional Materials, Vol.26, No.35, 6359-6370, 2016
Printing Ultrasensitive Artificially Intelligent Sensors Array with a Single Self-Propelled Droplet Containing Nanoparticles
The fabrication and implementation of artificially intelligent sensor arrays has faced serious technical and/or cost-effectiveness challenges. Here, a new printing method is presented to produce a fully functional array of sensors based on monolayer-capped gold nanoparticles. The proposed printing technique is based on the so-called self-propelled antipinning ink droplet, from which evaporative deposition takes place along the path of motion. By applying actuating forces, different deposition line patterns with different thicknesses and morphology from a single droplet are generated. The functionality of the produced sensors is demonstrated by their ability to detect different representative volatile organic compounds (VOCs) belonging to different chemical families, including alcohols, alkanes, ethers, and aromatics, and under extremely different humidity levels resembling those encountered in real-world conditions. The results show that the sensors exhibit ultrasensitive sensing features, with an ability to detect and differentiate between different VOCs at low ppb levels. Additionally, the results show that the sensors are able to accurately predict VOC concentrations, viz. enable quantification capabilities, while nevertheless being inexpensive, do not need complicated and expensive printing equipment and prepatterning processes, allow low voltage operation, and provide a platform for multifunctional applications.