Fig. 4: Actuation performance of fluid-driven homochiral hollow-fibre actuators.
From: Microfluidic manipulation by spiral hollow-fibre actuators
a Optical and infrared images of a PEHF580-990 actuator lifting a 10-g load in 1.2 s when flowing 90 °C water at a flow rate of 1.72 g s−1. b Maximum contraction at different masses of the load for 10 consecutive heating-cooling cycles of homochiral PEHF580-990 actuators with a spring index of 4.0 and an inserted twist of 300 turns m−1 driven by alternatively flowing 90 °C and 25 °C water. c Work capacity of PEHF580-990 actuators with different inserted twist densities and applied loads. d Work capacity of PEHF actuators with different sheath ratios at different loads. e Comparison of the work capacity for nylon 6 actuators made of hollow and solid fibres at different loads. The isobaric stress in d and e was calculated as the weight of the load divided by the cross-sectional area of the hollow fibre sheath. f Comparison of the specific work capacity of nylon hollow fibres in this work with that of single-filament pure-polymer fibre actuators in previous studies. The specific work capacity is defined as E/(m·Δθ), where E denotes the work output, m denotes the mass, and Δθ is the temperature change.
