Development and Integration of Inkjet-Printed Strain Sensors for Angle Measurement of an Origami-Based Delta Mechanism

Abstract

An origami-based parallel mechanism is an excellent solution for various applications where small-scale, low profile and foldability are needed. These mechanisms are composed of rigid and flexible layers designed according to layer-by-layer fabrication methods. In addition, it becomes important to design functional layers that provide user feedback. Here, the design and fabrication of an origami-based 3 Degree-of-Freedom (DoF) Delta mechanism, which has the same traditional kinematics as a Delta mechanism, are presented. A sensor layer was designed composed of 3 strain gauges to measure the angular position of the actuated arm of the mechanism. The strain-gauge patterns were printed on a special Polyethylene terephthalate (PET) using Silver nanoparticle ink with a commercial desktop printer. The integration of these sensors has been studied by placing them in different locations between rigid layers. The sensors' outputs were presented when subjected to step and sinusoidal inputs of the actuated arm. The experiment results show that the developed sensor layer can track the angular position changes of the actuated lower arm, which is a promising result to be used in a control loop in the feature.