Material and mechanical emulation of the human hand

  • Nick Hockings

Student thesis: Doctoral ThesisPhD

Abstract

The hands and feet account for half of the complexity of the musculoskeletal system, while the skin of the hand is specialised with many important structures. Much of the subtlety of the mechanism of the hand lies in the soft tissues, and the tactile and proprioceptive sensitivity depends on the large number of mechanoreceptors embedded in specific structures of the soft tissues.This thesis investigates synthetic materials and manufacturing techniques to enable building robots that reproduce the biomechanics and tactile sensitivity of vertebrates – histomimetic robotics.The material and mechanical anatomy of the hand is reviewed, highlighting difficulty of numerical measurement in soft-tissue anatomy, and the predictive nature of descriptive anatomical knowledge. The biomechanical mechanisms of the hand and their support of sensorimotor control are presented.A palate of materials and layup techniques are identified for emulating ligaments, joint surfaces, tendon networks, sheaths, soft matrices, and dermal structures. A method for thermoplastically drawing fine elastic fibres, with liquid metal amalgam cores, for connecting embedded sensors is demonstrated.The performance requirements of skeletal muscles are identified. Two classes of muscle-like bulk MEMS electrostatic actuators are shown theoretically to be capable of meeting these requirements. Means to manufacture them, and their additional application as mechanoreceptors are described.A novel machine perception algorithm is outlined as a solution to the problem of measuring soft tissue anatomy, CAD/CAE/CNC for layup of histomimetic robots, and sensory perception by such robots.The results of the work support the view that histomimetic robotics is a viable approach, and identify a number of areas for further investigation including: polymer modification by graft-polymerisation, automated layup tools, and machine perception.
Date of Award24 May 2017
LanguageEnglish
Awarding Institution
  • University of Bath
SponsorsEngineering and Physical Sciences Research Council
SupervisorPejman Iravani (Supervisor) & Christopher Bowen (Supervisor)

Keywords

  • Histomimetic
  • robot
  • robotic hand
  • composite materials
  • hand anatomy
  • Soft Tissue
  • hyperelastic
  • stretchable wires
  • machine perception
  • tendons
  • tendon mechanics
  • ligament
  • joint
  • preflex
  • underactuation
  • thermoplastic welding
  • artificial muscle actuator
  • tactile sensing
  • visual-tactile fusion
  • smoothed particle hydrodynamics

Cite this

Material and mechanical emulation of the human hand
Hockings, N. (Author). 24 May 2017

Student thesis: Doctoral ThesisPhD