Updated: Jul 6, 2022
PneuBots is a modular soft robotics construction kit consisting of seven types of self-foldable segments with high tensile strength, three types of pneumatic connectors and splitters, and a custom-designed box. The kit enables various assemblies to be made with the modular pieces, allowing creators to explore the world of soft robotics in playful ways. When combined with a FlowIO device, PneuBots allows seamless programmability of the different assemblies, enabling artists, designers, engineers, and makers to create dynamic, shape-changing, and interactive works that can be used for education, storytelling, dynamic art, or expression of affect and gratitude.
The PneuBots kit contains modular self-folding blocks that actuate when air is pumped in, We created structures fabricated out of sheet materials with heat-sealed hinges that fold when inflated. Four hinge types (inner patterns) were used to achieve different bending behaviors: linear, diagonal, diamond, and wide diamond. A module with a linear pattern has a 5mm gap in the middle of each straight line, which causes axial contraction during actuation. As the volume of the inflatable increases, the length of the linear pattern gap decreases and the height increases. The diamond shape-hinge serves as the bending angle control. The seam will continue to curve, and the hinge continue to bend, until the volume in the inflatable is maximized. Lastly, the diagonal pattern with a 5mm gap serves as the curling control, which is useful for changing the orientation of connected modules. Seven PneuBots modules with different actuation behaviors - including shrinking, curling, and bending - were designed. Two of those modules, the star-shaped and triangle-shaped, don’t have any hinges and thus have no folding action under actuation.
Modularity The different design patterns heat-sealed on the modular blocks constrain their deformation to yield a specific shape change under inflation. Each of the modules can be connected to one or more identical or different modules, thus enabling a diverse range of configurations, structures, and applications to be explored seamlessly and playfully. Each modular design features small, standardized units that can be independently combined in various configurations to create different forms and provide multiple functions. Our goals for designing modules were to identify what modules will be part of the planned system and what their functions will be; identify how different modules will connect to each other; and explore the performance of the modules in various arrangements.
Connectors Each PneuBots module has between one and five pneumatic ports with oral-inflation-valves that are commonly used on beach balls and swimming tubes. Some of the modules have more than one port, allowing air to flow in or out from multiple holes, and the users can choose which holes are open and which they wish to close with the plugs. Modules can be connected to each other using three types of pneumatic connectors: Straight- shaped, T-shaped, and Cross-shaped. (A) Straight connector allows multiple modules to be daisy-chained. (B) The T-shaped connector allows for more complicated assemblies. It also allows a single module with multiple inflation valves to connect to another one of its valves, which can be useful for achieving certain aesthetic outcomes. (C) The Cross-shaped connector allows up to four modular blocks to be connected to each other.
The PneuBots kit was preliminarily distributed to graduate students from backgrounds in architecture, engineering, and education, who were then tasked with experimenting and brainstorming possible uses for the modular blocks. For most users, this was their first exposure to soft robotics, and in the process, they learned about pneumatic control, actuation patterns, and heat-sealing fabrication. Our preliminary evaluation with the students showed that PneuBots enabled them to playfully create projects including a rolling robot, a wearable device, a gripper with two arms, and several artistic creations.