Abstract
Photothermal films used in flexible and wearable devices are inevitably exposed to mechanical deformation, yet their thermal response under such conditions remains poorly quantified. In this work, gold nanoparticle–embedded polydimethylsiloxane (Au@PDMS) films are fabricated and their photothermal behavior is examined under controlled stretching, bending, twisting, and curved-surface attachment. Gold nanoparticles were formed in situ in the PDMS matrix, producing uniformly dispersed, spherical nanocrystals with retained crystallinity. Systematic variation of Au loading reveals a proportional increase in optical absorption and light-to-heat conversion efficiency without significant aggregation. Under near-infrared irradiation (808 nm), the Au@PDMS films exhibit rapid and repeatable temperature modulation. Mechanical deformation alters the photothermal response in a deformation-mode-dependent manner: tensile stretching leads to gradual temperature reduction, and twisting and bending introduce predictable thermal modulation associated with geometric and structural changes. These effects are linked to deformation-induced variation in nanoparticle spacing and effective light absorption. To assess performance under realistic conditions, the film is applied to a curved tumbler surface, where spatial temperature variation reflects local mechanical deformation. By referencing strain–temperature relationships obtained under controlled loading, local stress distribution on the curved surface is inferred. This study demonstrates that photothermal response can serve not only as a heating function but also as a deformation-sensitive signal, offering a practical strategy for evaluating mechanically adaptive photothermal films in soft-device applications.