Fibrous materials and textiles for soft robotics

Soft, mechanically compliant robots are developed to safely interact with a “human environment”. The use of textiles and fibrous (composite-) materials for the fabrication of robots opens up new possibilities for “softness/compliance” and safety in human-robot interaction. Besides external motion monitoring systems, textiles allow on-board monitoring and early prediction, or detection, of robot-human contact. The use of soft fibers and textiles for robot skins can increase the acceptance of robots in human surroundings. Novel topology optimization tools, materials, processing technologies and biomimetic engineering allow developing ultra-light-weight, multifunctional, and adaptive structures

Woven piezoelectric sensors as part of the textile reinforcement of fiber reinforced plastics

Sensor integration in fiber reinforced plastic (FRP) structures enables online process and structural health monitoring (SHM). This paper describes the development and application of woven fabric-based piezoelectric impact and bending sensors for integration into FRP. The work focuses on design and characterization of woven piezoelectric sensors, especially as a part of the reinforcement structure. The reinforcement of the component acts as a sensor in itself and therefore no additional external objects in the form of sensor components or sensor fibers, which could create unwanted weak points within the FRP, are added. The bending test results reveal a direct relationship between the applied load and the sensor signal. Furthermore, the appropriate sensor position in the component cross section was determined and the influence of thermal polarization on the sensor properties was investigated

Utilization of the textile reinforcements of fiber reinforced plastics as sensor for condition monitoring

In addition to increased safety by detecting possible overload, continuous component monitoring by sensor integration makes the use of fiber reinforced plastics more cost-effective. Since the components are continuously monitored, one can switch from time-based to condition-based maintenance. However, the integration of conventional sensor components causes weak points, as foreign objects are inserted into the reinforcing structure. In this paper, we examine the use of the textile reinforcement as a sensor in itself. We describe how bending sensors can be formed by slightly modifying in the composite’s reinforcement structure. We investigated two different sensor principles. (1) The integration of textile plate capacitors into the structure; (2) The construction of textile piezo elements as part of the reinforcing structure. The bending test results reveal that textile plate capacitors show a load-dependent signal output. The samples with textile piezo elements show a significant increase in signal strength