A mosquito is known to precisely and easily insert its proboscis to the human skin by pressing down a labium and vibrating a fascicle bundle. Its advanced skin-piercing mechanisms indicate that skin resistance to the insertion of needle-like objects can be changed by the application of mechanophysical stimuli. Here, we characterize the effect of the application of mechanophysical stimuli on skin resistance to microneedle insertion to find clues for inserting a microneedle in a deep and precise fashion with low force. Microneedles with a diameter of 60–140 µm are inserted at a velocity of 0.1–2.0 mm/s to full-thickness porcine skins while either uniaxial/equibiaxial stretch of 0–20% or mechanical vibration at a frequency of 1 to 1000 Hz and an amplitude of 1–10 µm is applied to the skins as static or dynamic mechanophysical stimulus, respectively. The values of force and depth at two events of skin puncture and maximum penetration are measured to explore changes in skin resistance induced by the application of external stimuli. The static mechanophysical stimulus applied to the skin mainly affects the precision of microneedle insertion; the application of dynamic mechanophysical stimulus controls the value and deviation of skin resistance to microneedle insertion. The application of mechanophysical stimuli, inspired from a mosquito, therefore allows a microneedle to be deeply and easily inserted to the skin in a controlled way. The findings will have broad impacts on microneedle-mediated applications and lead to an in-depth understanding of skin biomechanics.

已知一种蚊子，其通过压下阴唇并振动束束来将其长鼻精确且容易地插入人的皮肤。其先进的刺穿皮肤机制表明，通过施加机械物理刺激可以改变皮肤对插入针状物体的抵抗力。在这里，我们表征了机械物理刺激的应用对皮肤对微针插入的抵抗力的作用，以寻找线索来以低的力以深而精确的方式插入微针。将直径为60–140 µm的微针以0.1–2.0 mm / s的速度插入全厚度的猪皮中，同时单轴/等轴拉伸为0–20％或机械振动以1到1000 Hz的频率和1–10 µm的振幅分别作为静态或动态机械物理刺激施加到皮肤上。测量在两次皮肤穿刺和最大刺穿情况下的力和深度值，以探索由于施加外部刺激而引起的皮肤抵抗力的变化。施加在皮肤上的静态机械物理刺激主要影响微针插入的精度。动态机械物理刺激的应用可控制皮肤对微针插入的抵抗力的值和偏差。因此，受蚊子启发而施加机械物理刺激，可以使微针以受控的方式深入并轻松地插入皮肤。