All-printed, low-cost, tunable sensing range strain sensors based on Ag nanodendrite conductive inks for wearable electronicsElectronic supplementary information (ESI) available. See DOI: 10.1039/c8tc04753g

Flexible and wearable strain sensors with high stretchability and high sensitivity have been studied intensively. However, the achievement of low-cost, rapid mass production and high performance of wearable strain sensors remains a challenge. In this study, Ag nanodendrite (ND) inks with good printability for varieties of substrates are prepared, which can be directly screen-printed onto nitrile rubber to manufacture strain sensors. Printed strain sensors (PSSs) with diverse working strain ranges and sensitivities can be simultaneously obtained by printing versatile geometric patterns. Comparatively, straight-line PSSs with a linewidth of 2 mm exhibit high electrical conductivity (1.14 × 10 5 S m −1 ), a large sensing range (105%), high sensitivity (maximum gauge factor = 294.3), an ultrafast response time (18 ms), and long-term stability (more than three weeks). Additionally, the sensing mechanism of the PSSs is further investigated by observing their surface topographies. Eventually, a smart glove based on PSSs is used for monitoring human motion (finger bending, wrist bending, walking, etc. ) and gesture actions, demonstrating the potential applications of Ag ND-based PSSs in wearable electronic devices and human-machine interaction intelligent systems. Stretchable and wearable strain sensors based on Ag nanodendrites with high stretchability and sensitivity are fabricated by directly screen-printing technology.