Spatially Engineered Co‐Axial Fibrous Electrodes of TPU / PLA Core– PVA / Tauseef Ahmed, Rajan Jose, Shafarina Azlinda Ahmad Kamal, Tamrin Nuge, Mohammad Obaidur Rahman, Nabihah Sallih, Syed Muhammad Hafiz, Adel Mohammed Al‐Dhahebi, Mohamed Shuaib Mohamed Saheed

ABSTRACT

Multifunctional flexible electrodes that combine mechanical flexibility, strain sensitivity, and electrochemical activity are attractive for wearable electronics used in biomechanical sensing and energy storage. However, combining flexibility, conductivity, strain sensitivity, and electrochemical charge storage ability within a single free‐standing polymeric material remains challenging due to the intrinsically insulating nature of flexible polymers. In this work, a free‐standing, all‐polymer co‐axially electrospun membrane comprising a TPU/PLA core and a PVA/PANI emeraldine salt (PANI‐ES) shell was fabricated via co‐axial electrospinning for simultaneous biomechanical strain sensing and pseudocapacitive charge storage. The four‐polymer architecture spatially differentiates the constituent functions of mechanically flexibility and electrical conductivity such that the flexible TPU/PLA core supports tensile deformation, maintains fibrous‐network continuity. Whereas the PVA/PANI‐ES shell provides strain‐responsive electrical conduction and electrochemically active redox sites. Intermolecular interactions within the PVA/PANI‐ES shell and TPU/PLA core promoted phase cohesion and supported the formation of continuous core–shell fibers. Among the investigated compositions, the membrane containing 0.2 g of PANI‐ES exhibited the most favorable balance among conductive‐phase availability, fibrous porosity, mechanical deformability, and ion accessibility. The optimized membrane achieved an elongation at break of approximately 78.8%, a gauge factor of ~60 at 25% strain, and an areal capacitance of 530 mF cm ⁻² at 2 mA/cm ² in a three‐electrode configuration. These results demonstrate that the performance arises not merely from combining four polymers, but from their deliberate spatial organization within a co‐axial fibrous architecture. The proposed design provides an all‐polymer route for integrating strain sensing and pseudocapacitive charge storage within a lightweight, flexible, and free‐standing membrane.