A 3D-printed stretchable strain sensor for wind sensing

Abstract

Stretchable strain sensors with large strain range, high sensitivity, and excellent reliability are of great interest to applications in soft robotics, wearable devices, and structure-monitoring systems. Unlike conventional template lithography-based approaches, 3D-printing can be used to fabricate complex devices in a simple and cost-effective manner. In this paper, we report 3Dprinted stretchable strain sensors that embed a flexible conductive composite material in a hyperelastic substrate. Three commercially available conductive filaments are explored, among which the ETPU from Rubber3D Printing, Sweden, shows the highest sensitivity (gauge factor of 20), with a working strain range of 0%-12.5%. The ETPU strain sensor exhibits an interesting behavior where the conductivity increases with the strain. In addition, the resistance change of the ETPU sensor in a doubly-clamped configuration in response to a wind stimulus is characterized, and the sensor shows sensitivity to wind velocity beyond 3.5 m s −1 . The experimentally identified material parameters are used in finite-element modeling and simulation to investigate the behavior of the 3D-printed stretchable strain sensor when subjected to wind loading. In particular, the model-predicted sensor output at different wind speeds, obtained with the computed sensor strain and the experimentally characterized strain-resistance relationship, achieves good match with the experimental data.

3D Printing of Flexible Strain Sensor Array Based on UV‐Curable Multiwalled Carbon Nanotube/Elastomer Composite

“…In comparison to most of the other strain sensors printed by FDM and extrusion 3D printing, [54][55][56][57][58][59] the strain sensor reported in this work has higher sensitivity, with more stable electrical properties and better detective limitation. Although the sensitivity of the developed sensor in this work is lower than the DLP-based sensor reported by Wang's group [33] and the FDM-based sensor reported by Al-Rubaiai et al, [60] the electromechanical performances of stretchability, mechanical durability, and detection limit of the sensor in this work are much enhanced.…”

A 3D-Printed Soft Fingertip Sensor for Providing Information about Normal and Shear Components of Interaction Forces

“…This settling time is visible in the bottom-right graph of Figure 10 after 675 s, where after the last cycle the resistance of the material slowly decreases. This behavior is not uncommon for conductive polymer composite materials [ 8 , 18 ] and corresponds to the time-dependence stress–strain curves for TPU materials [ 17 ]. We note that the initial resistance drop at low strain values may be related to alignment of conductive carbon black particles in the TPU material, whereas at higher strains breaking down of these networks may be causing the increase in resistance, as proposed in [ 8 ].…”

3D-Printed Load Cell Using Nanocarbon Composite Strain Sensor

“…Christ et al fabricated TPU/MWCNT strain sensors using 3D printing and evaluated their electrical properties [ 25 ]. Al-Rubaiai et al fabricated stretchable strain sensors using 3D printing for wind sensing [ 26 ]. Stano et al fabricated load cell structures and sensor parts with an FFF method using TPU and CNT filaments [ 27 ].…”