Validation of Thermoplastic Urethane Substrates for Stretchable Circuits: Experimental and Simulation Approach

Stretchable circuits with horseshoe-shaped conductors embedded in elastic polymersPolymer are susceptible to failure due to the accumulation of high plastic strain within the interconnects. This paper presents a study focused on validating the stability and performance of thermoplasticThermoplastics urethaneUrethane (TPU) substrates, which serve as the underlying substrate for stretchable circuitry. The validation process involved a combination of experimental and simulation techniques. First, a series of quasi-static uniaxial tensile tests were conducted on TPU substrates to assess their mechanical behavior. The stress–strain (S–S) curves obtained from the experiments demonstrated consistent and stable mechanical properties across the tested samples. The upper and lower boundary errors were computed to evaluate the deviation of stressStress concentrations from the mean stressStress value, indicating the stability of the TPU substrates. Next, finite element analysis (FEA) using Abaqus software was performed to validate the simulation model of the TPU substrate. The simulation results were compared with the experimental data, and a low error rate was observed, confirming the accuracy and reliability of the simulation model. The validated TPU model serves as a reliable representation of the substrate for stretchable circuits. The findings of this study contribute to the development of robust simulation models for predicting the growth of plastic strain within the components of stretchable circuits, enabling the identification of areas prone to high stressStress and strain. These insights are crucial for designing and optimizing stretchable circuitry for various applications.