Advances in printable flexible and stretchable thin-film electrodes: materials, interfaces, technologies and bioelectronic applications

Clinical Snapshot

Key Findings

• P Value: Not reported — narrative review format; no statistical testing conducted

• Effect Size: Not applicable — no primary data generated; no pooled effect sizes reported. Individual primary study performance metrics are cited qualitatively within the narrative

• Primary Outcome: Synthesis of advances in printable flexible thin-film electrode technologies, with emphasis on functional ink materials, interfacial adhesion engineering strategies (physical interlocking and chemical anchoring), and application domains including wearable electronics, implantable neural interfaces, and organoid bioelectronics

• Nnt Or Sensitivity: Not applicable — no clinical diagnostic, therapeutic, or prognostic outcomes are quantitatively synthesised. Engineering performance benchmarks (e.g., conductivity, stretchability thresholds) from primary studies are referenced descriptively without pooled estimates

• Confidence Interval: Not reported — no meta-analytic synthesis performed

Clinical Application

Clinical feasibility remains limited in the near term. While the materials science and fabrication advances described are technically compelling, significant barriers persist: regulatory approval pathways for novel bioelectronic materials are lengthy; long-term in vivo biocompatibility of functional inks (particularly ionogels and conductive polymers) requires rigorous human safety data; manufacturing reproducibility at clinical scale is unproven; and sterilisation compatibility of flexible substrates is not addressed. Wearable applications (e.g., skin-mounted ECG or EMG electrodes) are closer to clinical readiness than implantable systems. In Australia, bioelectronic medical devices are regulated by the Therapeutic Goods Administration (TGA) under the Therapeutic Goods Act 1989. Novel implantable electrode systems would require inclusion on the Australian Register of Therapeutic Goods (ARTG) and would be subject to conformity assessment. Wearable electrophysiological devices may qualify for lower-risk classifications depending on intended use. The PBS does not currently list flexible bioelectronic monitoring systems, and MBS item numbers for novel electrophysiological monitoring modalities would require Health Technology Assessment (HTA) evaluation through the Medical Services Advisory Committee (MSAC). Australian research groups, including those affiliated with the Australian Research Council Centre of Excellence for Electromaterials Science (ACES), are active in related bioelectronics research, providing a domestic scientific context. RACGP guidelines do not currently address flexible electrode-based monitoring, though this technology may eventually intersect with chronic disease management frameworks for cardiac and neurological conditions. Patients requiring long-term electrophysiological monitoring (e.g., epilepsy, cardiac arrhythmia, neuromuscular disorders), candidates for implantable neural interfaces (e.g., brain-computer interface recipients, cochlear implant users), and individuals using wearable biosensing devices. Application is currently largely preclinical; direct patient applicability requires further clinical validation.

Abstract

The mechanical mismatch between rigid clinical electrodes and soft biological tissues remains a primary bottleneck restricting the stability of long-term electrophysiological monitoring. Printable flexible thin-film electrodes offer a compelling solution by enabling additive, high-throughput patterning on flexible and stretchable substrates, thereby circumventing the reliance on vacuum environments and high-temperature processing typical of conventional microfabrication. This review synthesizes recent advances in functional inks, ranging from metals and carbon nanomaterials to conductive polymers and ionogels, together with high-resolution printing techniques. Addressing the critical challenge of interfacial failure in flexible devices, we explore engineering strategies to enhance adhesion at both electrode-substrate and electrode-tissue interfaces. Specifically, we analyze the pivotal roles of physical interlocking and chemical anchoring mechanisms in suppressing dynamic delamination and maintaining device integrity. Finally, the review highlights representative applications in wearable electronics, implantable systems, and emerging organoid interfaces, and outlines key translational challenges, including long-term stability and manufacturing reproducibility.

References

1. 1.Gu, B., Zhao, H., Long, F., Li, Q., Zhao, Y., Yu, M., Hu, X., Li, G., Han, F., Tian, Q., Liu, Z., & Yu, H. (2026). Advances in printable flexible and stretchable thin-film electrodes: materials, interfaces, technologies and bioelectronic applications. Nanoscale. https://doi.org/10.1039/d5nr05522a