We developed and presented highly sensitive solvent-free silver nanoparticle strain sensors fabricated using the aerodynamically focused nanoparticle (AFN) printer. The nanoparticles were printed in various conductive patterns. We explored how printer scan velocity affected pattern geometry and sensor sensitivity. The strain sensors were highly sensitive; the scan velocity afforded tunable sensitivity; and an analytical model predicted the behavior well under low-strain (<0.4%) conditions. We describe a prototype sensor that reliably measured composite beam tensile strain. We further enhanced the sensitivity by creating mechanical cracks, facilitating small dynamic signal measurements. The linear sensitivity of the sensor could be tuned from 18.60 to 290.62 by varying the scan velocity from 2 to 40 μm/s. The cracked sensor afforded the greatest sensitivity (1056) and captured small vibrations from a stringed instrument. We report highly sensitive and reliable measurements of dynamic behavior with simple tunability.
Keywords: aerodynamically focused nanoparticle printer; nanoparticle packing ratio; printed nanoparticle sensor; strain sensor; tunable sensitivity.