Echinoderm stereom gradient structures enable mechanoelectrical perception

Cellular solids ubiquitously exist in natural systems and are crucial for living organisms1,2. Their unique smooth branch and node morphologies are often seen as adaptations for enhanced mechanical performance3,4. Exploring alternative evolutionary functions can enrich the understanding of cellular solids, but it is frequently neglected. Here we show that the biomineralized cellular solids in echinoderm stereom (for example, sea urchin spine) have unexpected mechanoelectrical perception with response potential and response time, both of which are one to three orders of magnitude greater than those of echinoderm vision5. This exceptional perception originates from the gradient cellular solids (with varying…