Ultrafine three-dimensional (3D) laser lithographic fabrication of microneedle and its application to painless insertion and blood sampling inspired by mosquito

In the way of biomimetic research, we have developed a painless needle mimicking mosquito´s proboscis. A real three-dimensional (3D) sharp and jagged needle shape elaborately like mosquito, however, was difficult to achieve as far as using conventional fabrication methods. For this purpose, a 3D laser lithography with ultrafine resolution of 200 nm (0.2 μm) is employed in this article. Unlike other reported sole needles, presented microneedle is divided into two half parts, each is shaped like eaves-trough and dependently moved. The combined halves act as one hollow microneedle, which can draw up human blood by capillary action. The resistive force during insertion can be reduced when the two halves are alternately advanced, which mimics the motion of mosquito´s proboscis.