Biomimetic Barbed Microneedles for Highly Robust Tissue Anchoring

We present a bioinspired tissue-anchoring technology enabled via direct laser writing (DLW). 3-D printed barbed microneedles, mimicking the parasitic spiny-headed worm, display excellent structural fidelity/resolution and demonstrate −0.6 mN penetration force and 25 mN pull-out force when characterized on porcine small intestine tissue. Compared to the state-of-the-art barbed microneedles, the results indicate a significant advancement with approximately two orders of magnitude lower penetration force and over ten-fold higher pull-out/penetration ratio (PPR). The ease of tissue penetration and strength of attachment characteristics allow a more passive anchoring mechanism, with lower actuation and power requirements, for use in minimally invasive gastrointestinal (GI) resident devices.