Scientists from the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Sciences have created a “life-like” hydrogel. It gradually changes shape after one flash of light and continues to “evolve” for up to four weeks. The work was published in the scientific journal Matter1, it was reported by the South China Morning Post2.
NOTE
In short: one flash of near-infrared light triggers a slow chemical reaction in the hydrogel that goes on for weeks and changes its shape. On this principle, the authors made a substrate that affects what stem cells turn into, and electrodes that “grow up” together with the brain of young rats.
How it works
The system was named** sters * * (* spatiotemporally evolving reactive species*). It consists of three components1:
- ** gallium-based liquid metal particles ** — they produce active particles (radicals and ions);
- vinyl monomers — "building blocks" of the gel that react with gallium particles and support the production of active particles;
- near-infrared light (wavelength 808 nm) — it starts the process and sets where there will be more active particles.
After one irradiation, a gradient of active particles occurs in the gel, and it persists for up to 4 weeks. All this time, the particles start polymerization, and the gel is "cross-linked" at different places with different densities. Due to uneven stitching, the material gradually changes shape — from microscopic details to visible to the eye and in minutes to weeks. Irradiation can be repeated to trigger new cycles of change.
The authors borrowed the idea from wildlife. Organisms change shape not only quickly, like plant leaves, but also slowly, like tissues in the process of growth, and for this they need a constant source of active chemicals12.
EXPERIMENTS
Cell, Mother
The gel was placed between silicone films with microgrooves, and mesenchymal stem cells were grown on this substrate. The results depended on the width of the grooves1:
| Option | Groove width | What cages turned into |
|---|---|---|
| without irradiation | 9.8 μm, does not change | into bone (osteogenic differentiation) |
| one irradiation | narrows to 9.2 μm in 6 days | mainly in bone, but weaker |
| re-irradiation on day 3 | narrows to 8.7 µm | in neuron-like (neural differentiation) |
Thus, the authors showed that by changing the shape of the substrate with light, it is possible to direct the development of cells at a distance.
Growing Brain Electrodes
Conventional electrodes for recording brain activity retain one shape. As the brain and skull grow, the electrode ceases to fit snugly and the signal is lost. The authors applied the gel to a flexible 30-channel electrode array and recorded an electroencephalogram (EEG) ** in young rats from the 14th to the 28th day after birth**1.
On the 14th day, the new and conventional electrodes worked the same way. By the 21st and 28th day, the “growing” electrodes fixed a more complex picture of the connections of neural networks, because they were better adjacent to the developing brain.
Study leader Professor Du Xuemin (Du Xuemin) noted that this approach allows you to more accurately track changes in brain waves and study how the brain develops. According to him, the speed and scale of the change in the shape of the hydrogel can be adjusted to changes in the tissue under study 2.
IMPORTANT
Some retellings say that the electrodes recorded the brain activity of the rat's * * embryo * *. In the article itself, we are talking about ** postnatal * * development: experiments were conducted on two-week-old rats (P14-P28), and not on embryos1.
This may come in handy
The authors themselves call such areas12:
- flexible frames for tissue engineering and regenerative medicine;
- neurointerfaces and bioelectronics that adapt to growing tissues;
- soft robotics and "humanoid" robots.
So far, these are laboratory experiments on cells and animals. More research is needed prior to medical use, including on the long-term safety of materials.
Publishing
Nie M., Peng M., Li X., Xu W., Hua J., Galluzzi M., Du X. Self-sustaining reactive species program morphological evolution across timescales in hydrogels // Matter. 2026. Vol. 9. Article 103004. DOI: 10.1016/j.matt.2026.103004 Received April 26, 2026 and accepted August 8, 2026.
Researchers at the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Sciences have created a "lifelike" hydrogel. After a single flash of light it gradually changes shape and keeps "evolving" for up to four weeks. The work was published in the scientific journal Matter1 and reported by the South China Morning Post2.
NOTE
In short: one flash of near-infrared light starts a slow chemical reaction inside the hydrogel that runs for weeks and reshapes it. On this principle the authors built a substrate that steers what stem cells turn into, and electrodes that "grow" along with the brains of young rats.
How it works
The system is called STERS (spatiotemporally evolving reactive species). It has three components1:
- gallium-based liquid metal particles, which generate reactive species (radicals and ions);
- vinyl monomers, the building blocks of the gel, which react with the gallium particles and keep the reactive species coming;
- near-infrared light (808 nm wavelength), which starts the process and sets where the reactive species are concentrated.
A single exposure creates a gradient of reactive species in the gel that lasts up to 4 weeks. Throughout that time the species drive polymerization, so the gel crosslinks more densely in some places than in others. This uneven crosslinking gradually changes the material's shape, from microscopic features to ones visible to the naked eye, over periods from minutes to weeks. Irradiation can be repeated to start new cycles of change.
The authors took the idea from living nature. Organisms change shape not only quickly, like plant leaves, but also slowly, like tissues as they grow, and they need a sustained source of reactive chemical species to do so12.
Experiments
Stem cells
The gel was placed between silicone films with microgrooves, and mesenchymal stem cells were grown on this substrate. The outcome depended on the width of the grooves1:
| Setup | Groove width | What the cells became |
|---|---|---|
| no irradiation | 9.8 µm, unchanged | bone-type cells (osteogenic differentiation) |
| one irradiation | narrows to 9.2 µm over 6 days | mostly bone-type, but weaker |
| second irradiation on day 3 | narrows to 8.7 µm | neuron-like cells (neural differentiation) |
This showed that reshaping the substrate with light can steer cell development remotely.
Electrodes for a growing brain
Conventional electrodes for recording brain activity keep a fixed shape. As the brain and skull grow, the electrode stops fitting snugly and signal is lost. The authors added the gel to a flexible 30-channel electrode array and recorded electroencephalograms (EEG) in young rats from postnatal day 14 to day 281.
On day 14 the new and conventional electrodes performed the same. By days 21 and 28 the "growing" electrodes captured more complex neural network connectivity, because they fit the developing brain better.
The study's lead, Professor Du Xuemin, said the approach makes it possible to track changes in brain waves more precisely and to study how the brain develops. According to him, the speed and scale of the hydrogel's shape change can be tuned to match changes in the tissue being studied2.
IMPORTANT
Some retellings say the electrodes recorded the brain activity of a rat embryo. The paper itself is about postnatal development: the experiments used two-week-old rat pups (P14–P28), not embryos1.
Possible uses
The authors point to these directions12:
- flexible scaffolds for tissue engineering and regenerative medicine;
- brain–machine interfaces and bioelectronics that adapt to growing tissue;
- soft robotics and humanlike robots.
So far these are laboratory experiments on cells and animals. Medical use would require further research, including into the long-term safety of the materials.
Publication
Nie M., Peng M., Li X., Xu W., Hua J., Galluzzi M., Du X. Self-sustaining reactive species program morphological evolution across timescales in hydrogels. Matter. 2026. Vol. 9. Article 103004. DOI: 10.1016/j.matt.2026.103004. Received April 26, 2026; accepted August 8, 2026.
- Nie et al., Matter (2026), https://doi.org/10.1016/j.matt.2026.103004; PDF on the institute's website: https://ibmd.siat.ac.cn/uploads/file/2026-09-07/6a9e1f2ee7d154.21528948.pdf ↩
- South China Morning Post, "Chinese team creates‘ lifelike ’hydrogel that changes shape for smart devices": https://www.scmp.com/news/china/science/article/3369897/chinese-team-creates-lifelike-hydrogel-changes-shape-smart-devices ↩