目的 利用非光滑表面减阻技术设计仿生无痛针头并探讨其无痛机理。方法 从减阻角度出发，根据蚊子吸血不痛的特点，在分析蚊子口器结构基础上，设计两种仿生减阻无痛针头（锯齿形和条纹形），并运用显示动力学分析软件LS-DYNA，对常规光滑表面针头和仿生针头的软组织注射过程进行数值模拟，分析仿生针头的减痛机理。结果 通过对比分析光滑针头和仿生针头软组织穿刺过程的应力云图、内能曲线和阻力曲线可知，仿生针头具有明显减阻效果，锯齿形针头和条纹形针头减阻率分别为23.84%和31.57%。结论 仿生针头可以通过减阻来达到减痛或无痛注射效果，且仿生针头结构形态决定其减阻效果。

Objective To design a kind of bionic drag reduction needle and investigate its mechanism of painless injection. Methods Based on the analysis of mosquito's mouthpart structure, two types of bionic drag reduction injector needles, sawtooth needle and stripe needle, were designed with the painless feature as mosquito's blood-sucking action. The injection processes of normal smooth needle and two bionic drag reduction injector needles were simulated by using explicit kinetic software LS-DYNA, and analyzed the pain-relief mechanism of bionic drag reduction needles. Results Through contrast and analysis on the stress contour, internal energy curves and resistance curves of both the smooth needle and bionic needles during the puncturing process in soft tissue, the bionic needle was found to have obvious drag reduction effects. The drag reduction rate of the saw-tooth needle and stripe needle was 23.48% and 31.57%, respectively. Conclusions The bionic needles can minimize the friction resistance to achieve the painless injection by drag reduction, and its effect is determined by the structure and shape of the bionic needle.

国家自然科学基金资助项目（50875108），中国博士后科学基金资助项目(801114202418)