Imagine a flexible electronic patch that adheres to your skin to monitor your health, but it stops working after a few bends of your joints; or a minimally invasive surgical robot with a sensitive "touch" that becomes sluggish after repeated operations. These "durability" problems that have plagued the development of the flexible electronics industry are being jointly solved by a group of undergraduate students at Northwestern Polytechnical University, with an average age of only 20. The innovation team, composed of eight students from different majors including Deng Yifan, Liu Yudong, and Wang Yuze, has spent three years working on the core reliability issues of stretchable electronic devices and achieved breakthrough progress, contributing youthful wisdom to the "robust growth" of the trillion-dollar flexible electronics market. Their research results have been published in an internationally renowned academic journal, demonstrating the vigorous vitality of young Chinese researchers.
Flexible electronics are hailed as a key track in future technology, widely applied in health monitoring, human-machine interaction, and other fields. However, existing devices tend to "malfunction" after repeated stretching and bending due to material fractures and interlayer delamination, akin to the "growing pains" of electronic devices, severely restricting their reliability and lifespan. "When we conducted research in hospitals, we noticed that flexible devices used for joint monitoring often failed after a short period of use. This is due to the insufficient coordinated design of materials, structures, and interfaces," said team leader Deng Yifan, explaining the team's research motivation: to make flexible electronic devices truly "flexible" and "durable."
Interdisciplinary collaboration sparks innovation
Facing the key challenge of "cross-scale failure," this group of undergraduates chose the direction of "multi-scale coordinated design." Their diverse academic backgrounds became a unique advantage but also presented initial challenges. "Material ratios, electronic integration, mechanical analysis - each step requires knowledge from different disciplines. We held regular interdisciplinary discussions every week and often debated until late at night over a single issue," recalled team member Liu Yudong. It was this cross-disciplinary collaboration that enabled them to quickly establish a systematic research framework covering "substrate - materials - interfaces - devices."
Repeated trials and errors to overcome core bottlenecks
Finding the "golden ratio" of materials:
To make the flexible substrate both rigid enough to support electronic components and flexible enough to adapt to deformation, the material ratio is crucial. Their initial attempts were repeatedly frustrated: the materials were either as brittle as ice, shattering at the slightest touch, or as soft as cotton, unable to bear weight. The team spent their days in the laboratory adjusting the formula and used computer simulations at night to find patterns. After over 200 trials and errors, they finally discovered the key "code" - by precisely controlling the content of a special molecular group, they successfully developed a new type of substrate material that combines rigidity and flexibility, with a tensile capacity far exceeding traditional materials.
"Mediating" incompatible material partners:
After solving the substrate performance issue, the conductive materials liquid metal (LM) and MXene were still difficult to mix uniformly due to their "incompatible personalities," leading to unstable conductivity. The team conducted numerous experiments and eventually found a "mediator" and optimized the mixing process. In an ice bath, with the help of ultrasonic waves, they enabled the two materials to "shake hands" - the spontaneously formed oxide layer on the surface of the liquid metal became the "bridge" connecting them, constructing a stable and efficient ternary conductive network.
Securing the "easily separating" interface:
When the substrate and conductive layer each performed well, the team discovered in the 2024 tensile test that the interface between them still tended to "separate" after repeated stretching. "When magnified hundreds of times, the traditional physical adsorption interface looks like a sand pile, falling apart as soon as it's stretched," explained team member Huang Kanghuan. They tried various methods to enhance the bonding force and finally, through unique surface treatment technology and the synergistic effect of chemical bonds, they significantly increased the "synchronous strain rate" of the interface to over 95%. This means that even after 1,000 repeated stretches, the device's conductive performance can still remain at a high level of 90%.
From the laboratory to the dawn of the future
Based on these breakthroughs, the team has ultimately fabricated a stretchable pressure sensor that maintains accurate and reliable signal responses even under significant deformation, with performance indicators approaching commercial standards. Even more excitingly, they have adopted a light-curing 3D printing process to achieve an "integrated" manufacturing process from material design to device formation, paving the way for future large-scale production. "When tested in the national key laboratory, the engineers were all astonished that an undergraduate team could produce such a device that is both high-performance and feasible in terms of manufacturing," said a team member with pride.
Over the past three years, this group of young people has completed the entire process from literature research to technical breakthroughs and patent layout, conducting over 4,000 material tests and 1,200 hours of computer simulations, and establishing an efficient "experiment-simulation-optimization" R&D closed loop. Academician Huang Wei of the Chinese Academy of Sciences commented, "This research approach that directly addresses industrial pain points and integrates multidisciplinary wisdom fully demonstrates the innovative potential of the younger generation to break conventions."
When asked how undergraduates can challenge cutting-edge technology, the team members gave a unanimous answer: "Interdisciplinary studies have broadened our thinking, and our acute perception of actual needs keeps the research on track and vibrant." Now, some members are about to be recommended to top universities at home and abroad for further studies, but they have agreed to continue holding weekly online seminars to keep delving into the fertile ground of flexible electronics.
From countless adjustments of material formulas in the laboratory to future wearable health devices and precise medical robots, this young "00s" team has proven through their actions that when the spark of curiosity meets industrial demands, and when multidisciplinary wisdom meets the persistence of youth, even in the uncharted territory of the technological frontier, undergraduates can carve out a new world, injecting youthful energy into the strong "pulse" of China's flexible electronics.