# Shape-Memory–Assisted Self-Healing and Real-Time Acidic Environment Detection in Multifunctional Electrospun Fibers

## TL;DR

This paper introduces electrospun fibers that can self-heal and detect acidic environments, offering potential for smart textiles and wearable electronics.

## Contribution

A novel multifunctional fiber platform integrating shape-memory self-healing and acid-triggered color change is developed.

## Key findings

- TPU-rich blends enable self-healing efficiencies up to 95% and stable chromic reversibility.
- PCL-rich blends show larger diameters, reduced chromic response, and incomplete recovery.
- The platform combines shape-memory, self-healing, and acid detection in a single fiber system.

## Abstract

Smart fiber systems that integrate self-healing and environmental
responsiveness are emerging as promising candidates for wearable electronics,
protective clothing, and adaptive textiles. Here, we report a multifunctional
electrospun fiber platform combining shape-memory–assisted
self-healing with acid-triggered chromism. The fibers are fabricated
from thermoplastic polyurethane (TPU)/poly­(ε-caprolactone) (PCL)
blends doped with the acid-sensitive dye ODB-2. Distinct thermal transitions
of TPU and PCL enable programmable deformation and recovery, whereby
fractured fibers self-heal through thermally activated interfacial
diffusion. Meanwhile, ODB-2 undergoes a reversible structural change
upon protonation, producing a visible color contrast that functions
as an acid-responsive optical signal. Systematic characterization
of chemical structure, morphology, and functional performance reveals
a clear compositional dependence. TPU-rich blends yield uniform fiber
morphologies, stable chromic reversibility over multiple acid–base
cycles, and self-healing efficiencies up to 95%. In contrast, PCL-rich
compositions exhibit larger fiber diameters, reduced chromic response,
and incomplete mechanical recovery. These results demonstrate how
polymer composition governs both structural features and functional
outcomes. By integrating shape-memory, self-healing, and chromic responsiveness
into a single platform, this work establishes a versatile design strategy
for smart polymer fibers capable of damage repair and real-time environmental
monitoring. The approach offers broad opportunities for developing
next-generation wearable electronics, intelligent textiles, and adaptive
membranes for use in corrosive or dynamically fluctuating environments.