Abstract
This study presents a method for printing flexible chemiresistors comprising thin film transducers based on cross-linked gold nanoparticles (GNPs). First, interdigitated silver paste electrodes are printed onto polyimide (PI) foil via dispenser printing. Second, coatings of GNPs and dithiol/monothiol blends are inkjet-printed onto these electrode structures. 1,9-Nonanedithiol (9DT) is used as cross-linking agent and a variety of monothiols are added to tune the sensors’ chemical selectivity. When dosing these sensors with different analyte vapors (n-octane, toluene, 4-methyl-2-pentanone, 1-butanol, 1-propanol, ethanol, water; concentration range: 25–2000 ppm) they show fully reversible responses with short response and recovery times. The response isotherms follow a first-order Langmuir model, and their initial slopes reveal sensitivities of up to 4.5 × 10−5 ppm−1. Finally, it is demonstrated that arrays of printed sensors can be used to clearly discern analytes of different polarity.
Highlights
Thin films of ligand-stabilized or cross-linked noble metal nanoparticles are interesting materials for applications as highly responsive physical and chemical sensors
The protocol for the fabrication of flexible gold nanoparticles (GNPs)-based chemiresistors developed in this study is based on the combination of standard printing technologies without the need of additional lithographic process steps
Printing of GNPs and cross-linker was repeated until the baseline resistance of the sensor was in the low megohm range
Summary
Thin films of ligand-stabilized or cross-linked noble metal nanoparticles are interesting materials for applications as highly responsive physical and chemical sensors. Thin films of gold or silver nanoparticles deposited onto flexible substrates or prepared as freestanding membranes can be used as highly sensitive resistive strain [1,2,3,4] or pressure sensors [5,6,7] Such sensors have been proposed for applications in modern health care and medical devices, e.g., for human motion detection, pulse wave analysis, and voice recognition [8,9,10,11]. The high sensitivity of GNP-based chemiresistors is attributed to the high permeability of nanoparticle assemblies and a perturbation-sensitive charge transport mechanism based on thermally activated charge carrier tunneling [15] Further advantages of these sensors are their short response and recovery times and the possibility to operate them at room temperature. GNP-based chemiresistors can be operated with low power consumption and they can be fabricated on various polymer substrates, such as polyethylene (PE), polyethylene terephthalate (PET), or polyimide
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
