倾斜仿生刚毛的设计、制备及黏附性能研究

Design,Fabrication and Adhesion Test of Lean Bio-inspired Seta

依据JKR理论,从几何仿生角度出发设计并制备了2种具有斜截面的倾斜人工刚毛.理论计算表明:刚毛支杆倾斜20°,斜截面为45°时,刚毛具有较为理想的黏附性能,且具有这种结构的刚毛可便利地调控吸附和脱附.利用微摩擦试验机测试了人工刚毛表面的黏附性能,结果表明:在无滑移的平面接触下,刚毛阵列的黏附力随法向载荷增加而增大,当法向载荷超过一定值后,黏附力增加缓慢并趋于饱和;法向载荷为30mN时,刚毛无滑移卸载所产生黏附强度约为2.4kPa,略高于逆向滑移后卸载所产生的黏附强度2.2kPa,而正向滑移后卸载所产生的最大黏附强度较逆向滑移后卸载有明显增加,达3.1kPa,增加了近41%;短距离的滑移可增加黏附力,但随着滑移距离加大,黏附力随之下降.

Two kinds of lean setae with lean cross surfaces were designed from JKR theory and fabricated under vacuum condition. Theoretical calculation indicated that the resulted setae had desired adhesion property when the lean angle was about 20° and cross surfaces angle was about 45°. In addition, it is also convenient to control the attachment and detachment of setae. The universal micro tribometer -2 （UMT -2） system was used to examine the anisotropic adhesion of the setae. Results showed that the adhesion force increased with the increase of the normal load under flat - to - flat contact and finally came to the maximum adhesion force of 2.4 kPa under a preload of 30mN; the adhesion of sliding against the setae was about 2.2 kPa, a bit lower than that without sliding. While sliding along the setae, the adhesion reached 3.1 kPa, increased roughly by 41% relative to sliding against the setae. The adhesion increased within a small slide, then, decreased with the increasing distance.