以蚊子和蝉的口针为原形设计了凹槽形仿生针头,运用试验优化技术,通过显示动力学接触分析,证明凹槽形仿生针头具有明显减阻效果,最高减阻率可达40.94%;分析凹槽针头表面非光滑几何形态参数对注射时针头外壁所受摩擦力的影响规律,凹槽深度对摩擦力影响最大,宽度对摩擦力影响最小,凹槽深度和宽度与摩擦力呈抛物线关系,凹槽条数与摩擦力呈线性关系,随着凹槽条数增加,摩擦力减小;探讨仿生针头减阻机理,针头凹槽结构的存在可减小针头外壁与软组织的接触面积,使软组织与针头表面间存在间隙,产生空气膜,降低摩擦因数,另一方面,可使皮肤中的液体易于逸出,增加了润滑效果。依据国标,对数值分析所用的9种凹槽形仿生针头进行了穿刺试验,试验结果与数值分析结果一致。
Taken the microstructure of mosquitoes and cicada mouthparts as the prototypes, one groove shape bionic needle is design. The conclusion that the groove shape bionic needle has obvious resistance reduction effect is proved through contact dynamic analysis using the method of orthogonal design of experiment. The highest resistance reduction rate can amount to 40.94%; the influence law between the non smooth geometry parameters and the friction on the needle external wall getting in the injecting process is found out. The greatest impact factor of the friction is the groove depth, the minimum width. The relationship between the groove depth, width, and friction is a parabola. The relationship between groove number and friction is linear. The groove number increases, friction decreases. The influence order of factors and optimal levels are determined. The existence of the needle groove structure can reduce the contact area of the needle outer wall and soft tissue and this gap can produce a film of air, reducing the friction coefficient. On the other hand, the liquid can make the skin easy to escape, increasing lubricating effect. According to GB, the puncture tests of nine groove shape bionic needles are taken and the test result has been consistent with the numerical analysis result.