Development of three bundled microneedles mimicking mosquito's mouthparts and characterization of effect of their synchronous movements and serrations on decreasing puncture resistance

In recent years, there has been a demand for the development of minimally invasive puncture devices, e.g., needle-like tools that can reduce the pain and stress on patients in medical procedures, such as blood collection and blood glucose testing. We focused on mosquito's mouthparts for painless blood sucking during its puncture behavior. Observation revealed that the puncture was conducted by three synchronously vibrating needles: the labrum (hollow needle for bloodsucking) and a pair of maxillae (solid needle with serrations). In this study, three stainless steel microneedles fabricated by femtosecond laser processing were bundled and synchronously moved, mimicking mosquito's mouthparts. The needles' puncture performance on artificial skin made of PDMS (polydimethylsiloxane, a kind of silicone rubber) was characterized by experiments and was analyzed by nonlinear FEM (finite element method). The effectiveness of synchronous vibration and serrations was confirmed; they decrease the puncture resistance force and the compressive stress; while increase the shear stress to tear the skin thanks to serrations working as anchors.