Freestanding Thin-Film Materials

TL;DR

This review discusses the fabrication, properties, and applications of freestanding thin-film materials, highlighting their advantages, challenges, and future prospects in flexible electronics, sensors, and quantum devices.

Contribution

It systematically summarizes fabrication techniques, explores unique properties, and discusses emerging applications and challenges of freestanding thin films.

Findings

Advanced fabrication methods enable high-quality freestanding films.

Unique mechanical and interface properties facilitate novel device applications.

Challenges remain in scalable production and long-term stability.

Abstract

Freestanding thin films, a class of low-dimensional materials capable of maintaining structural integrity without substrates, have emerged as a forefront research focus. Their unique advantages-circumventing substrate clamping, liberating intrinsic material properties, and enabling cross-platform heterogeneous integration-underpin this prominence. This review systematically summarizes core fabrication techniques, including physical delamination (e.g., laser lift-off, mechanical exfoliation) and chemical etching, alongside associated transfer strategies. It further explores the induced strain modulation mechanisms, extreme mechanical properties and interface decoupling effects enabled by these films. Representative case studies demonstrate breakthrough applications in flexible/ultrathin electronics, ultrahigh-sensitivity sensors and the exploration of novel quantum states. Critical challenges regarding scalable fabrication, precise interface control, and long-term stability are analyzed, concluding with prospects for emerging applications in bio-inspired intelligent devices, quantum precision sensing, and brain-inspired neural networks.