Venus fytrap can sense the very small insects that touch its tactile receptors, known as trigger hairs, and thus capture prey to maintain its nutrient demand. However, there are few studies on the trigger hair and its morphological structure and material properties are not fully understood. In this study, the trigger hair is systematically characterized with the help of diferent instruments. Results show that trigger hair is a special cantilever beam structure and it has a large longitudinal diameter ratio. Besides, it is composed of a hair lever and a basal podium, and there is a notch near the hair base. The crosssection of the trigger hair is approximately a honeycomb structure, which is composed of many holes. Methods to measure mechanical properties of trigger hair are introduced in this paper. Based on the mechanical tests, trigger hair proved to be a variable stifness structure and shows a high sensitivity to the external force. These features can provide supports for the understanding of the high-sensitivity sensing mechanism of trigger hairs from the perspective of structure and material, and ofer inspirations for the development of high-performance tactile sensors.
Experimental designs: a, b the procedure of measuring Young’s modulus of trigger hair. a Fixation of the sample; b diagram of AFM indentation. c–e The procedure of measuring the elastic coefficient of trigger hair. c Selection of sample; d fixation of the sample; e diagram of the experiment: 1, glue; 2, trigger hair; 3, glass substrate; 4, probe tip; 5, cantilever; 6, holder chip; 7, lobe
This work is carried out by Qian Wang1,2 · Kun Xu1 · Cheng Fan1 · Lining Sun1 · Lei Zhang1 · Kejun Wang1,2
1 Jiangsu Provincial Key Laboratory of Advanced Robotics,
Soochow University, Suzhou 215021, China
2 Key Laboratory for Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, China
and published on JBE Volume 18, Issue 5, September 2021, Pages 1126–1136 https://doi.org/10.1007/s42235-021-00082-z