Stretchable multimodal sensor arrays for hardness perception in bionic skin

Bionic skin technologies are central to advancing robotic perception and human–machine interaction, with multimodal sensing being a critical enabler. A recent study led by Professor Yuan Lin’s team at the University of Electronic Science and Technology of China presents a highly integrated, stretchable sensor array capable of simultaneously detecting pressure, strain, and inferring material hardness without requiring external displacement measurements. This work offers a promising path toward high-resolution, intelligent tactile systems for robotics and wearable devices.

The sensor array is fabricated using scalable methods such as laser etching and chemical plating, integrating 100 pressure and 18 strain sensing units in a compact coplanar configuration. A key innovation lies in the embedded serpentine island–bridge structure that allows high stretchability and mechanical isolation, ensuring functional stability under large deformations. This structural design was validated through finite element analysis (FEA), confirming localized strain buffering and minimal crosstalk between units under up to 20% tensile strain.

The pressure sensors exhibit a sensitivity of about 0.008891 kPa⁻¹ with rapid response time, while the strain sensors demonstrate a gauge factor of about 15.2. The multimodal nature of the system enables not only pressure–strain mapping but also accurate hardness distribution imaging, a feature crucial for tasks like object manipulation and material recognition in robotics.

To demonstrate real-world application, the system was to classify fruits with different hardness levels and maturity stages. A deep learning framework (SE-ResNet) was trained on combined pressure and strain data, achieving a remarkable 100% classification accuracy, showing the potential of this system for advanced tactile feedback in prosthetics, soft robots, and smart wearables.

Looking ahead, the research team plans to optimize spatial resolution and integrate temperature compensation mechanisms to enhance robustness. The presented approach sets a new benchmark in soft electronics by bridging high-density integration, mechanical resilience, and intelligent data fusion in one platform. As the demand for real-time, high-resolution tactile sensing grows across human–machine interfaces, this multimodal sensor array offers a scalable and practical solution for next-generation electronic skin.

The team published their review in Nano Research on November 26, 2025.

This work was supported by the National Natural Science Foundation of China under Grants 62427806, 62201119 and U21A20460, Guangdong Basic and Applied Basic Research Foundation under Grant 2023A1515010975, Shenzhen Science and Technology Program under Grant JCYJ20230807120009019.

About Nano Research

Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.