Researchers in China have developed a fully stretchable moisture-powered generator designed to keep wearable electronics running even under repeated bending and stretching.

The team from Harbin Institute of Technology said the device overcomes one of the biggest challenges facing hydrogel-based moisture-electric generators of weak adhesion between the hydrogel and electrode layers. Poor bonding often causes unstable electrical output and mechanical failure during deformation.

Hydrogel moisture-electric generators have attracted growing attention because they can convert moisture in the environment into electricity while remaining soft and flexible. Such systems are being explored for wearable electronics, implantable devices, and health-monitoring technologies that require lightweight and continuous power sources.

However, many existing systems struggle to maintain stable output once stretched, twisted, or bent repeatedly. The researchers said weak interfacial interaction between the hydrogel and electrodes often increases resistance and causes layer separation, limiting both electrical performance and long-term durability.

Stretching without performance loss

To solve the issue, the researchers engineered a highly adhesive hydrogel that strengthens the interface between the functional layers and electrodes. The hydrogel was swollen in a water-glycerol solvent and integrated with liquid metal and stretchable silver electrodes to build the generator.

According to the study, the addition of glycerol exposed more hydrogen-bonding groups inside the hydrogel, increasing contact points between the hydrogel and electrodes. This improved adhesion while also lowering interfacial resistance, helping ions move more efficiently through the device under strain.

The researchers also found that glycerol improved the hydrogel’s resistance to drying, freezing, and swelling, enabling long-term stable operation in different environmental conditions.

The team used both experiments and simulations to verify the system’s performance. They reported that the adhesive hydrogel reduced interfacial impedance and improved ion transport efficiency compared to conventional structures.

Using AIMD simulations and DFT calculations, the researchers further confirmed that the reinforced hydrogel-electrode interface enabled faster ion migration and lowered the energy barrier for ion movement.

Built for wearables

The device achieved an output voltage exceeding 0.94 volts and a current density of 141 microamps per square centimeter, according to the researchers. The team said the electrical output remained stable even when the system was subjected to repeated deformation.

The generator also demonstrated strong mechanical durability. After 1,040 stretching cycles, the system continued operating stably. Even after 8,000 bending cycles at a 180-degree angle, the researchers observed negligible performance degradation.

The researchers believe the technology could support wearable electronics that need flexible and stable energy sources during daily movement. Potential applications mentioned in the study include respiration-monitoring systems and self-powered health sensors.

By stabilizing the hydrogel-electrode interface, the researchers said the work offers a broader strategy for improving reliability in soft electronic systems where mechanical stress often damages performance over time. The approach could also help guide future development of flexible energy devices capable of operating under demanding environmental and mechanical conditions.

The study was published in the journal Nano-Micro Letters.

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