Fabrication: Cardboard Mold

Introduction

A 3D printer is an invaluable tool in the fabrication of soft robots. Unfortunately, these printers are expensive and not generally considered household objects. Those who do not have the luxury of a 3D printer are able to purchase printer time. However, both the cost and the time constraints required to ship 3D print jobs can deter new soft robotics hobbyists from entering the field. This mold is designed for those interested in entering soft robotics. It is used to produce fiber-reinforced actuators and is easily constructed using readily attainable, affordable and often household materials such as cardboard and hot glue.     

Overall Design 

This mold is perfect for beginners because of its simple geometry and low cost. The mold is constructed out of two distinct parts. The first part of the mold is made up of a central block and a surrounding wall. This produces the flexible top half of the robot. The second part of the mold is created by layering hot glue on a flat surface. It is used to fabricate the bottom inextensible half of the robot.  To assemble the robot, both halves are bonded together and wrapped with ribbon.

This type of mold is not limited to individual actuators. The mold geometry can be modified to make more complex robots such as this soft robotic gripper.