All 3D-printed high-sensitivity adaptive hydrogel strain sensor for accurate plant growth monitoring

Highly sensitive strain sensors are crucial for monitoring subtle plant growth changes and show diverse applications in plant sensing. However, the prevailing integrated fabrication methods for such sensors tend to be costly and complex, impeding their fundamental design and practical usage. Herein, we develop a simple and effective multimaterial all-3D printing technique to manufacture integrated strain sensors with a multilayered structure. Such an all-3D-printed strain sensor exhibits excellent sensing performance enabling precise detection of minor strains in plant growth, including high stretchability (> 300%), high sensitivity (~12.78) with good linearity (0.98), and good long-term stability over 3,000 loading/unloading cycles. We further validate the potential applications of our 3D-printed integrated strain sensor for accurate and continuous monitoring of bamboo growth in both horizontal and vertical directions over 14 days. Our all-3D-printed strain sensor offers a promising avenue for integrated strain sensing systems toward plant growth monitoring.