Session: 12-20-01: Functional Origami and Kirigami-inspired Structures and Metamaterials

Paper Number: 111586

111586 - Design of an Extendable Robot Arm Based on Origami Foldpatterns 

In recent years, the trend to use robots in the household has increased significantly. So far, these are mostly
robots with fixed tasks and few degrees of freedom, such as vacuum cleaning robots or mowing robots. These
areas of application have the advantage that they usually operate in a fairly familiar environment and can
fulfill their tasks with their fixed configuration. However, if household robots are to perform more complex
tasks in the future, such as washing dishes or using the dishwasher, they must be lightweight, inexpensive and
be able to adapt to different environments in the household. Until now, this adaptation has largely been done
through the use of robotic structures, which consist of multiple rotational joints. However, when it comes to a
task that is not solvable with the current arm length configuration, it would be advantageous for these robots
to have variable length links (prismatic joints). In the following paper, it is shown how such a length-adjustable
robot arm is constructed. The special feature of this robot arm is that it is origami-based, which makes the
activating structure and the guiding structure the same. In addition, the convolution-based approach offers
the advantages of origami-based engineering. Due to the high number of kinematic overconstraines, which
are often created by repeating folding patterns, a very high stiffness can be achieved. In addition, the panelbased
design of folding based strucures allows the use of sandwich structured lightweight panels, which
greatly reduces the weight of these structures. The construction of this arm was made possible by the Matlab
toolbox "SG-Libary". This construction is automated, adapted to the user's requirements regarding the desired
retracted, respectively extended length of the robot arm. In the first step, the user defines the desired length
for the retracted and extended robot arm. Based on the Miura-Ori foldpattern, which consists of four fold
lines and has a degree of freedom of one, a ring element for the arm is designed. Subsequently, the required
length of the arm is achieved by repeating and coupling these ring segments and stored in the "FOLD" file
format. Using this folding pattern, the software then calculates for each joint in the fold pattern the angular
range in which that joint must move. With this angular information, the fold pattern is then automatically
constructed with the necessary angular limits and presented to the user in the form of a surface model. At this
point, this model already has fully constructed joints with angle limits, which prevent the individual folding
joints in the robot arm from getting into singular positions. The surface model can then be exported as an STL
file and produced using, for example, the SLS or SLA 3D printing processes. With the process shown in this
paper, a robotic arm was created and manufactured using SLS 3D printing. This robotic arm was then tested
for deformation with and without external load using an optical tracking method.

Presenting Author: Markus Huber Institute of Micro Technology and Medical Device Technology, Technical University of Munich

Presenting Author Biography: Markus Huber is a Research Assistant at the Institute of Micro Technology and Medical Device
Technology at TUM, Germany. His research focus on origami based engineering.
Markus Huber received his Bachelor’s degree (2018) in Mechanical Engineering and Master's
degree (2020) in Mechatronics from the University of Applied Science in Munich, Germany.
During his studies towards his Bachelor’s degree, he stayed at the University of Regina,
Canada, for an exchange study in Mechanical Engineering.

Authors:

Markus Huber Institute of Micro Technology and Medical Device Technology, Technical University of Munich
Judith Merz Institute of Mechanism Theory, Machine Dynamics and Robtics (IGMR), RWTH Aachen University
Christoph Rehekampff Institute of Micro Technology and Medical Device Technology, Technical University of Munich
Franz Irlinger Institute of Micro Technology and Medical Device Technology, Technical University of Munich
Tim C. Lueth Institute of Micro Technology and Medical Device Technology, Technical University of Munich