A high anti-impact STF/Ecoflex composite structure with a sensing capacity for wearable design

By encapsulating shear thickening fluid (STF) in Ecoflex-0030, a kind of composite structure with excellent anti-impact and high energy absorption properties was obtained. The drop hammer tests indicated that the increase of STF concentration could improve the anti-impact and energy absorption capacity of STF/Ecoflex. Furthermore, the loss rate of impact energy of STF/Ecoflex was 63.6% and 36.6% higher than that of aluminum alloy and Kevlar materials, respectively. Numerical simulation was used to explore the mechanism. It was found that the shear thickening effect of STF was enhanced with the increase of STF concentration, which could lead to the increase of the stress level of STF and the energy dissipated by friction and viscosity, thereby the anti-impact performance of the composite was improved. Then, the C-STF/Ecoflex was prepared by adding carbon nanotubes (CNTs) to STF, which had excellent impact sensing function and could be combined with Kevlar for multi-functional wearable devices with anti-impact properties.