A bimorph pneumatic bending actuator by control of fiber braiding angle

•A novel pneumatic bending actuator has been developed that generate bending motion with a single tubular actuator.•A highly controllable and robust fabrication technique suited for mass production is also proposed.•The pneumatic bending actuator has been modelled and validated with experimental results.

Typical pneumatic actuators provide one directional linear motion, but in many applications bending motion is required. Achieving bending motion with a typical pneumatic actuator requires a complex mechanism to translate the linear motion into bending. Hence, a bending pneumatic actuator will be desirable. This paper presents a bending pneumatic actuator that can be mass-produced. This actuator was modelled by using finite element analysis over a range of parameters. Systematic experimentation was carried out to validate the FEA simulations. A pneumatic bending actuator of length 180-220 mm, inner diameter 7-11 mm, wall thickness 2-3.2 mm, is capable of generating blocking force up to 7.32 N and bending angle up to 224.3° with an input pressure of 0.675 MPa and an operating switching frequency of 20 Hz with no more than 7% radial expansion for the samples under test. The low profile, light weight, compliant nature and robustness of the actuators developed in this work lead to a large variety of potential applications.