Root-Inspired Interfaces for Highly Stretchable Hybrid Electronics

Prof. Inkyu Park’s group at KAIST has developed a bioinspired interfacial design strategy that enables seamless integration of rigid and flexible components into stretchable electronic systems. Inspired by the mechanical interlocking behavior of plant roots in soil, the team engineered a “Bioinspired Interfacial-Engineered Flexible Island” (BIEFI) to overcome the mismatch in mechanical properties at rigid–soft interfaces, a longstanding challenge in stretchable electronics.

The BIEFI employs flexible root-like structures embedded in a soft elastomer to create a robust mechanical interlocking interface. Through systematic parametric optimization of root dimensions and arrangements, the researchers achieved an unprecedented 700% stretchability while maintaining electrical and mechanical reliability. Finite element analysis and digital image correlation studies revealed how the root geometry distributes strain and prevents interfacial failure through flexible interlocking mechanisms.

The research team demonstrated the applicability of BIEFI in various functional devices, including stretchable LED arrays, solar cell arrays, and a smart resistance band for real-time workout monitoring. Additionally, a stretchable pulse sensor was developed using the same platform to monitor cardiovascular signals. These demonstrations highlight the platform’s potential for wearable electronics, energy harvesting, and healthcare monitoring.

“This root-inspired interface offers a scalable and reliable solution for merging rigid, flexible, and stretchable elements, bringing us closer to commercial-grade stretchable electronics,” said Prof. Inkyu Park, the corresponding author from the Department of Mechanical Engineering at KAIST.

This study was published in February 2025 (Bioinspired interfacial engineering for highly stretchable electronics, Nature Communications, 16, 1337 (2025), https://doi.org/10.1038/s41467-025-56502-9). The work was supported by grants from the National Research Foundation of Korea (NRF), Institute of Information & communications Technology Planning & Evaluation (IITP), and the Ministry of Science and ICT (MSIT).