Over the last couple of decades, many people have regained hearing functionality with the most successful neurotech device to date: the cochlear implant. But for those whose cochlear nerve is too damaged for a standard cochlear implant, a promising alternative is an auditory brainstem implant (ABI).

Unfortunately, current ABIs are rigid implants that do not allow for good tissue contact. As a result, doctors commonly switch off a majority of the electrodes due to unwanted side effects such as dizziness or facial twitching—leading most ABI users to perceive only vague sounds, with little speech intelligibility.

Now, a team at EPFL’s Laboratory for Soft Bioelectronic Interfaces has developed a soft, thin-film ABI. The device uses micrometer-scale platinum electrodes embedded in silicone, forming a pliable array just a fraction of a millimeter thick.

This novel approach, published in Nature Biomedical Engineering, enables better tissue contact, potentially preventing off-target nerve activation and reducing side effects.