Study on asymmetric nature of thumbnail strain when grasping an object

2015 Fiscal Year Final Research Report

• Project/Area Number: 26560301
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Rehabilitation science/Welfare engineering
• Research Institution: Utsunomiya University
• Principal Investigator: Shimawaki Satoshi 宇都宮大学, 工学(系)研究科(研究院), 准教授 (10344904)
• Co-Investigator(Kenkyū-buntansha): SAKAI Naotaka 宇都宮大学, 大学院工学研究科, 教授 (90235119)
• Co-Investigator(Renkei-kenkyūsha): NAKABAYASHI Masataka 宇都宮大学, 大学院工学研究科, 助教 (50638799)
• Research Collaborator: TASHIRO Tomoya ; ITO Yasuaki
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 母指爪ひずみ / 物体把持 / 物体操作 / 把持力 / 有限要素法

Outline of Final Research Achievements

The purpose of this research was to measure thumbnail strain when grasping an object (cylinder, sphere, and flat plate) and to determine whether asymmetric strain distribution occurs in the radioulnar direction. In addition, we examined the effects of object size and thumb-pressing force. Biaxial strain gauges were attached at three locations on the thumbnail surface (central, radial, and ulnar parts). Each axis of the biaxial strain gauges was aligned to the axial and transverse directions, respectively. When object size was small, the distribution of strain in the axial and transverse directions was asymmetric; however, when object size became large, the asymmetric nature of the strain distribution in either one of the axes disappeared. When grasping a small object, the ulnar surface of the thumb pad is an important contact surface. This was the factor in asymmetric strain distribution occurring in the radioulnar direction.

Free Research Field

生体計測・福祉工学