Development of nanoparticle film-based multi-axial tactile sensors for biomedical applications

• A multi-axial tactile sensor based on cross-linked gold nanoparticle films is developed.
• The fabrication uses inkjet printing, and micro-molding techniques scalable to sub millimeter dimensions.
• Sensitivities of 0.037%/mN in the normal, 0.036%/mN in the shear x and 0.048%/mN shear y directions respectively were achieved.
• Dynamic characteristics showed minimal change in hysteresis and response for increasing strain-rates.
• We conclude the device is comparable with existing technology with advantages in linearity, physical flexibility and sensitivity.

Tactile feedback in biomedical applications, e.g. prosthetic artificial skin and minimally invasive surgery, requires multi-axial detection capabilities, with high sensitivity and reliability. This paper presents the fabrication, modeling and experimental characterization of a novel nanoparticle resistive-based multi-axial sensor over the range of 0–300 mN for use in tactile feedback. The fabrication uses inkjet printing, and micro-molding techniques scalable to sub millimeter dimensions. Sensitivities of 0.037%/mN in the normal, 0.036%/mN in the shear x and 0.048%/mN shear y directions respectively were achieved. Dynamic characteristics indicated minimal change in hysteresis (standard deviation – 1.2%) and response (standard deviation – 0.4%) compared with the applied load for increasing strain-rates.