CHINESE researchers have taken a notable step forward in flexible invasive brain‑computer interface (BCI) technology with a stiffness‑tunable probe dubbed the “Neurotentacle,” which they report can cut implantation damage by about 74%, Science and Technology Daily said.

The probe, developed at the Institute of Semiconductors of the Chinese Academy of Sciences (CAS), incorporates a miniature hydraulic actuation system. During implantation the device temporarily stiffens — described by the team as behaving like an inflated balloon — allowing it to penetrate brain tissue with precision; once in place, the hydraulic pressure is released and the probe softens, minimizing acute tissue damage and returning to a flexible state that better conforms to the brain’s microenvironment, the report said. The study was published online in Advanced Science on July 21.

Flexible neural microelectrodes have attracted growing interest in BCI and neuroscience because their compliance and biocompatibility tend to reduce immune responses and prolong device longevity in vivo. Compared with conventional rigid electrodes, flexible probes generally cause less mechanical trauma at insertion, produce milder chronic inflammatory responses, and can maintain stable signal quality for longer periods.

But extreme softness brings a practical challenge: as co‑author Pei Weihua explained, ultra‑soft materials often cannot penetrate dense brain tissue or reliably reach deep target areas without some form of temporary rigid support. Addressing this tradeoff between insertability and chronic tissue compatibility is a key engineering hurdle for flexible BCIs.

The Neurotentacle design aims to resolve that dilemma by providing on‑demand stiffness. In effect, the probe is rigid enough during the brief insertion phase to reach its target accurately, then reverts to a compliant state that reduces mechanical mismatch with surrounding tissue over the long term.

A team led by Liang Jing, a fellow at the CAS Institute of Psychology and a co‑author on the paper, validated the Neurotentacle in animal experiments. Compared with traditional microneedle‑guided implantation techniques, the researchers report the Neurotentacle reduced implantation‑induced damage by more than 74% and lowered chronic inflammation by roughly 40%.

(SD-Agencies)