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.

Soft robotics is an emerging and rapidly accelerating field with a very high potential for impact, which is also of strong interest to the Human Computer Interaction (HCI) and Haptic communities. Yet the barriers to entry for most researchers and makers are still very high, and those barriers are even greater for people who come from nontechnical backgrounds. Learning about soft robotics fabrication techniques became even more difficult in the wake of the COVID-19 pandemic. That's because most fabrication and prototyping processes necessitate expensive materials that are not readily available in most countries, space for molding and casting, computer aided design (CAD) skills, and access to equipment such as 3D printers. Additionally, the actuation and sensing of soft robots requires advanced skills in pneumatics, engineering, and programming.

Currently, there are only few examples of modular kits related to this field, and most of them are only research prototypes, not readily available to people. Chao Zhang wrote a comprehensive review paper in 2020 on modular soft robots that also lists nearly all known soft robotics construction kits. Two examples of reconfigurable soft robotic kits include InflatiBits and Soft LEGO. None of these are easy to access, and requires additional electronics background.

A constructive assembly kit in combination with carefully curated informational resources could significantly reduce the barrier to entry and allow people to easily get started with soft robotics, prototype basic interactions, develop intuition about the behavior and control of such robots, and be inspired and motivated to go beyond the offering of a kit. PneuBots, a novel soft robotics construction starter kit, is made from durable, low-cost inflatable materials. PneuBots includes a variety of building blocks with different actuation behaviors and comes with a FlowIO Platform that allows even novice users without any programming or electronics background to create soft robots with dynamic interactions and bring their creations to life.

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.

Each of the modules can be connected to one or more identical or different modules, thus enabling a diverse range of con- figurations, structures, and applications to be explored seamlessly and playfully. Modules can be connected to each other using three types of pneumatic connectors: Straight- shaped, T-shaped, and Cross-shaped. Straight connectors allow 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. Inspired by this fabrication method, some graduate design students developed inflatable structures with more complicated inner patterns, which include rectangles, circles, irregular shapes, and combination of different shapes. PneuBots has been very useful in helping students understand not only soft robotics and actuation mechanisms, but also the fabrication process of heating thin PVC film, sealing methods, and connections between silicone tubes and modular units.

For creative thinkers, designers, and engineers with the problem of accessing, understanding, and implementing emerging technologies such as soft robotics, we develop and produce user-friendly interfaces, connecting the dots between academic disciplines and more applied solutions in engineering, design, and other hands-on fields. Our aim is to support designers, artists, and developers in their exploration by providing them with soft robotics kits that are affordable, modular, programmable, and suitable to their creative visions. We want to inspire those unfamiliar with soft robotics to engage with a new way of thinking about structure and architecture and provide them with a straightforward learning and prototyping toolkit.