A CHINESE research team has advanced a “drop-printing” strategy that enables damage-free film transfer using droplets, offering key technical support for fields such as flexible electronics and brain-machine interfaces (BMI), according to a release published on the website of the Institute of Chemistry, Chinese Academy of Sciences (CAS).

The research team was led by Song Yanlin, a professor from the Institute of Chemistry, CAS, and supported by National Natural Science Foundation of China, Ministry of Science and Technology, CAS, and Beijing National Laboratory for Molecular Sciences, according to the release published Friday.

With the rapid rise of cutting-edge technologies such as wearable electronics, brain-computer interfaces, and neural rehabilitation, there is a growing need to attach precision electronic devices to organ tissues like a “second skin” for the collection and regulation of physiological signals. However, traditional attachment methods often result in significant internal stress within the devices, especially when applied to uneven surfaces of the skin, brain, or nerves. The fragile ultra-thin metal circuits and chips inside the devices are easily damaged due to stress concentration, which has become a major bottleneck for flexible electronics, the release noted.

The team, in collaboration with Beijing Tiantan Hospital affiliated with Capital Medical University and Nanyang Technological University, Singapore, proposed a novel transfer strategy for ultrathin film materials — “drop-printing,” according to the release.

Research shows that this technology can not only transfer non-ductile nanoscale metallic and silicon films onto the surfaces of optical fibers, plants, and even living cells without damage, but it can also achieve functions such as stem cell membrane transfer and bioadhesion by adjusting the composition of the droplets, according to the release.

In animal experiments, researchers printed and attached ultra-thin silicon-based electronic films onto the surfaces of mouse nerves and brains, creating a conformal, non-destructive bioelectronic interface. This enabled high spatiotemporal resolution infrared light modulation of the nerves, said the release.

The research article titled “Drop-printing with dynamic stress release for conformal wrap of bioelectronic interfaces” was published on Science recently. The study details a “drop-printing” strategy that enables damage-free film transfer with droplets. The droplet acts as a lubricating layer between the film and the target surface, facilitating local sliding during shape-adaptive deformation. This mechanism prevents in-plane film stretching and reduces stress concentration, according to the abstract of the research article.

(SD-Agencies)