Volume 13, Issue 2,April 2016, Pages 303–311
Jintian Linga, Lelun Jianga, Keyun Chena, Chengfeng Pana, Yan Lia, Wei Yuanb, Liang Liangb
a School of Engineering, Sun Yat-sen University, Guangzhou 510006, China
b School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China
Abstract
Worker honeybee pierces animal or human skin with its ultra-sharp stinger and injects venom to defend itself. The insertion behavior is a painless transdermal drug delivery process. In this study, Apis cerana cerana worker honeybee was chosen as the research object. The geometry and structure of the stinger were observed by the Scanning Electron Microscope (SEM). High-speed video imaging technique was adopted to observe the stinger insertion and pull behavior of honeybee. The skin insertion, pull-out, in-plane buckling and out-of-plane bending forces of honeybee stinger were tested by a self-developed mechanical loading equipment. Results showed that the honeybee stinger pierces directly into skin without frequent vibration. The pull-out force (average 136.04 mN) was two orders of magnitude higher than the penetration force (average 1.34mN). Compared with the penetration force, the in-plane buckling force (average 6.72 mN) was in the same order of magnitude. The result of out-of-plane bending test showed that the stinger was elastic and it could recover after bending. The excellent geometry and structure of honeybee stinger will provide an inspiration for the further improved design of microneedle-based transdermal drug delivery system.
Keywords
stinger; mechanical loading; penetration force; pull-out force; barbs
Full text is available at http://www.sciencedirect.com/science/article/pii/S1672652916603037