Chaudhri Buddhadev Paul, Ceyssens F, Neves H Pereira, La Manna A, Van Hoof C, Puers R
Interuniversity Microelectronics Center, Kapeldreef 75, 3001 Leuven, Belgium.
Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:3680-3. doi: 10.1109/IEMBS.2011.6090622.
This paper reports on the high strength of high-aspect ratio (> 50) hollow, polymer microneedles fabricated out-of-plane using a fairly repeatable fabrication process. Further, these microneedle tips were sharpened by a molding principle, with a simple anisotropic etch of silicon wafer. Also, an enhanced elegant process was explored to incorporate the mounting of the microneedle onto a platform without using any additional material, such that the bore of the microneedle is continuous with the bore of the platform in order to facilitate microfluidic delivery through the hollow needles. The high aspect ratio microneedles undergo failure at the critical load of around 4 N, while the insertion force for such a needle into agar gel, which is a fairly good equivalent of the human skin due to its inherent visco-elastic properties, is 7 mN, which translates into a safety factor (ratio of critical loading force to the maximum applied force) of greater than 500 thus, making it adequately strong for skin penetration.
本文报道了使用相当可重复的制造工艺在平面外制造的高纵横比（>50）中空聚合物微针具有高强度。此外，这些微针尖端通过成型原理进行锐化，采用简单的硅晶片各向异性蚀刻。而且，还探索了一种改进的精巧工艺，将微针安装到平台上而不使用任何额外材料，使得微针的孔与平台的孔连续，以便于通过中空针进行微流体输送。高纵横比微针在约4 N的临界载荷下会失效，而将这种针插入琼脂凝胶（由于其固有的粘弹性特性，它相当好地模拟了人类皮肤）的插入力为7 mN，这转化为安全系数（临界加载力与最大施加力之比）大于500，因此使其对于皮肤穿透具有足够的强度。
