Chinese scientists create record-smashing brain implant electrode array thinner than hair

A China-led team of researchers has developed a powerful brain implant electrode array that is as soft as brain tissue, thinner than a strand of hair and more durable than anything before it.In animal trials, a new flexible brain implant recorded neural activity with unprecedented long-term clarity and remained safely functional inside the body for 18 months.The breakthrough addressed a major hurdle that had long held back brain-computer interfaces.Invasive interfaces deliver the clearest and richest neural signals, yet a persistent challenge haunts invasive systems: the inherent mismatch between electrodes and soft brain tissue.The cortical electrode arrays commonly used today, typically made of platinum or platinum-iridium-alloys" class="entity-link entity-topic" data-entity-id="148919" data-entity-type="topic">platinum-iridium alloys, offer excellent conductivity but are far stiffer than neural tissue.The cortical electrode arrays commonly used today, typically made of platinum or platinum-iridium-alloys" class="entity-link entity-topic" data-entity-id="148919" data-entity-type="topic">platinum-iridium alloys, offer excellent conductivity but are far stiffer than neural tissue. Photo: ShutterstockIn long-term implantation, such “hard-against-soft” friction induces tiny relative displacements, triggering chronic inflammation and eventually forming scar tissue around the electrodes. The result is a steady decline in signal quality year after year.