Scientists Created a Hydrogel That Turns Body Movement Into Electricity—and Can Even Control Nerves

Imagine a soft material that can generate electrical signals simply when it is stretched, compressed, or bent—and can even use those signals to interact with the nervous system. Researchers are now developing a new type of smart hydrogel that could bring this idea closer to reality.

Called a piezoionic hydrogel, this material combines the softness and flexibility of biological tissues with the ability to generate electrical signals through the movement of ions. A new study led by Xiaodan Yang and colleagues introduces an improved design called an artificial ion pump (AIP) hydrogel, which produces a much stronger electrical response than conventional versions.

The breakthrough could open new possibilities for self-powered sensors, wearable electronics, implantable medical devices, and electrical nerve stimulation.

What Are Piezoionic Hydrogels?

Hydrogels are soft, water-rich materials that can resemble the mechanical properties of biological tissues. Because they are flexible and compatible with living systems, they are increasingly being explored for medical and electronic applications.

Piezoionic hydrogels take this concept further.

Instead of relying mainly on electrons moving through a conventional conductor, these materials generate electrical signals through the movement and redistribution of ions inside the hydrogel.

When mechanical force is applied—such as stretching, pressing, bending, or compressing—the internal structure of the hydrogel changes. This movement can cause mobile ions to shift from one region to another, producing a measurable voltage.

This phenomenon is known as the piezoionic effect.

The concept is particularly interesting for biological applications because our bodies naturally communicate using ions. Nerve cells, muscles, and other biological systems depend heavily on ionic movement to generate electrical signals.

However, there has been a major problem.

The voltage has been extremely low.

Although piezoionic materials can respond to mechanical movement, their electrical output has often been too weak for many practical applications. Researchers therefore needed to understand exactly how the internal structure of these materials affects ion movement and electrical performance.

The new study addresses this problem by focusing on a previously underappreciated property: tortuosity.

A New Way to Think About Ion Movement

In simple terms, tortuosity describes how complicated or winding a pathway is.

Imagine two roads connecting the same starting point and destination.

One road is straight, while the other contains countless curves and detours. Even though both roads connect the same places, vehicles can travel much more efficiently through the straight road.

Ion movement inside a hydrogel can work in a similar way.

In a conventional hydrogel, ions may encounter complicated and randomly arranged pathways. Instead of moving efficiently in one direction, they can spread through the material in different directions.

This random movement reduces the efficiency of directional ion transport—and ultimately weakens the electrical response.

Yang and the research team used tortuosity as a way to understand and control this behavior.

Their goal was straightforward: create more organized pathways that allow ions to move more efficiently in a preferred direction.

Building the Artificial Ion Pump

The researchers developed an artificial ion pump hydrogel with two important structural characteristics.

The first is low tortuosity, meaning the pathways available for ion movement are more organized and less complicated.

The second is an aligned porous structure that gives the hydrogel unusual mechanical behavior.

Together, these features allow the material to perform two important tasks at the same time:

move ions more efficiently and concentrate mechanical stress more effectively.

The researchers modified the surface polarity of the material and created aligned pores within the hydrogel.

These microscopic pores are not simply empty spaces. Their arrangement strongly influences how the material responds when mechanical force is applied.

How the Structure Improves Electricity Generation

When the AIP hydrogel is mechanically deformed, the aligned porous structure helps concentrate stress within specific regions.

Think about squeezing a sponge.

If the internal structure is randomly arranged, the force may spread in many directions. But if the internal structure is carefully aligned, the force can be transferred along particular pathways.

The AIP hydrogel takes advantage of this principle.

Its aligned pores help concentrate and amplify mechanical stress. This improves the transfer of force through the material and promotes greater displacement of mobile ions.

At the same time, the lower tortuosity provides more ordered pathways for those ions to travel.

This combination is important.

Better mechanical stress transfer + more efficient directional ion transport = stronger piezoionic response.

According to the researchers, the tortuosity factor was reduced to about 35%, significantly improving the organization of ion-transport pathways.

Instead of ions moving randomly through a complicated network, the structure encourages them to move in a more organized manner.

More Than 20 Times Higher Performance

The structural improvements produced a major increase in performance.

The new AIP hydrogel achieved a piezoionic coefficient more than 20 times higher than its unoptimized counterpart.

This is significant because increasing the electrical output of soft, ion-based materials has been one of the major challenges preventing their wider use.

Rather than simply changing the chemical composition of the hydrogel, the researchers demonstrated that controlling its microscopic architecture can dramatically improve its electrical behavior.

This provides a new design strategy for future piezoionic materials.

Instead of asking only, “What material should we use?” researchers can also ask:

“How should we arrange the material’s internal structure so that ions and mechanical forces move in the most useful way?”

Why This Matters for Medical Devices

One of the most exciting aspects of the technology is its potential use inside the human body.

Traditional electronic devices generally depend on rigid components, batteries, wires, and external power sources. These features can make long-term implantation challenging, particularly when devices need to interact with soft and constantly moving biological tissues.

Hydrogels offer a different approach.

Because they are soft and water-rich, they can be mechanically more compatible with biological tissues. A piezoionic hydrogel can also potentially generate electrical signals from natural body movements without requiring a conventional battery.

For example, movements caused by breathing, muscle activity, blood flow, or other physiological processes could potentially provide mechanical energy.

That mechanical energy could then be converted into ionic electrical signals.

Connecting the Hydrogel to the Nervous System

The researchers went a step further by testing the AIP hydrogel generator in a peripheral nerve regulation experiment in mice.

The device demonstrated an ability to synchronize with physiological rhythms while also influencing neural activity.

This result is particularly interesting because it suggests that the material could potentially act as a bridge between mechanical movements and biological electrical signals.

In the future, similar technologies could potentially contribute to implantable systems designed for self-powered sensing or electrical stimulation.

For example, an implant might harvest mechanical energy generated naturally by the body and use the resulting electrical signal to monitor physiological activity or provide controlled stimulation.

Such systems could reduce dependence on batteries and potentially simplify some types of implantable electronics.

A New Direction for Soft Electronics

The significance of this research extends beyond one particular hydrogel.

The study provides a clearer connection between microstructure and electrical performance in piezoionic materials.

The key lesson is that the internal architecture of a material can be just as important as its chemical composition.

By controlling pore alignment, surface polarity, ion pathways, and mechanical deformation, researchers can influence how efficiently ions move and how strongly the material responds to mechanical forces.

This could help researchers design the next generation of soft sensors, energy harvesters, artificial tissues, wearable electronics, and bioelectronic implants.

There are still challenges before such systems become widely used. Researchers will need to improve long-term stability, reliability, energy output, biocompatibility, and manufacturing methods. They will also need to determine how these materials perform under the complex conditions found inside the human body.

Nevertheless, the AIP hydrogel demonstrates an important principle: tiny structural changes at the microscopic level can produce enormous differences in macroscopic performance.

The Bigger Picture

The human body is constantly moving. The heart beats, lungs expand, muscles contract, blood flows, and tissues deform.

Most of this mechanical energy is simply dissipated.

Piezoionic hydrogels offer a fascinating possibility: turning some of that movement into useful electrical signals while using materials soft enough to interact with biological tissues.

The artificial ion pump hydrogel developed by Yang and the team shows how carefully engineered internal pathways can make this process far more efficient.

With its 35% tortuosity factor, aligned porous architecture, more than 20-fold improvement in piezoionic performance, and demonstrated ability to interact with peripheral nerve activity, the technology represents a promising step toward self-powered bioelectronics.

The future of medical electronics may not always require rigid chips and batteries.

It could involve soft, flexible materials that move with our bodies, harvest energy from that movement, and communicate directly with biological systems.

Reference: Xiaodan Yang, Yi Zheng, Ying Hong, Shiyuan Liu, Xuemu Li, Liang Wang, Zhuomin Zhang, Weikang Lin, Tongxin Chen, Riran Liang, Zhenqi Wang, Xiaote Xu, Qiqi Pan, Jianjun Wu, Zhengbao Yang; Built-In Ion Pump Piezoionic Hydrogel Generator for Self-Powered Electrical Stimulation. ACS Appl. Mater. Interfaces 25 February 2026; 18 (7): 10934–10947. https://doi.org/10.1021/acsami.5c23169