8. Soft robotics

Exploring Soft Robotics

This week’s class introduced us to a fascinating field: soft robotics! Unlike the rigid robots we’re used to, soft-bodied robots are designed to mimic living organisms or the human body, giving them more natural movements and adaptability. 🌱🤖

What’s Soft Robotics All About?

Soft robotics is about creating flexible, adaptive robots, often designed to imitate characteristics from nature. This field heavily relies on bio-inspired design or biomimicry, aiming to create robots that can perform unique functions in areas that rigid robots cannot. Here’s where soft robotics is making an impact:

• Wearable Tech 👕: Enhancing mobility and adapting comfortably to the human body.
• Rehabilitation Prosthetics 🦾: Creating supportive and adaptable prosthetics.
• Surgical Robots 🏥: Offering more precision and flexibility during surgeries.
• Rescue Operations 🚑: Navigating tight spaces and complex terrains with ease.

References & Inspiration

I’ll be gathering some really exciting references to showcase the potential of soft robotics.

Process and workflow

Anoush showed me how to make a paper balloon! The process was simple and really fun, even if my first try wasn’t perfect. I enjoyed seeing how just a bit of air could shape and move the paper, making it almost come to life. Working on the balloon helped me understand how air can act as a soft actuator, allowing objects to inflate and move in response.

Since I already had some experience with paper folding, I decided to dive deeper into this area and start experimenting. I created two paper structures that can actually change their shape! This was a fun challenge, as I got to explore how different folds and designs can transform with movement or air. Each piece showed how a flexible, folded structure could act like a soft robot, changing its form in response to forces applied to it. This hands-on practice is helping me understand the potential of soft robotics through simple materials.

The second one was especially interesting because it moves with the help of air!

I experimented by blowing into it to expand and open the shape further. It was so cool to see how a simple breath could bring the structure to life.

Experimenting with Silicone 🧪

This week, we also started working with silicone for soft robotics. Silicone is perfect for this because it’s flexible, durable, and can be molded into all kinds of shapes.

Mixing Silicone for Soft Robotics 🧪

For this part of our project, we used Epoxy Master platinum-based silicone 5A to create flexible structures. We carefully measured out 32.5 grams of Part A and 32.5 grams of Part B using a precision scale, making sure the quantities were equal. Once measured, we mixed the two parts thoroughly but very carefully to avoid creating air bubbles. This step is super important because any trapped air can interfere with the final structure's durability and flexibility. Mixing silicone requires patience, but it’s worth it to get a smooth, bubble-free result!

In addition to the Epoxy Master silicone, we also used 60 grams of Silicone 0A to make even more flexible soft robotic components. So, we ended up with two different silicone mixtures, each with unique properties for our experiments. The combination allowed us to explore a range of flexibility and movement in our designs, giving us more options to work with in our soft robotics projects!

To get the best results with our Epoxy Master platinum-based silicone, we placed the container on a vibration machine. This machine gently vibrates the mixture, helping any air bubbles rise to the surface and pop before the silicone cures.

Once our silicone mixture was bubble-free, we moved on to filling the molds. We already had some pre-made molds ready for our soft robotics parts, so we carefully poured the silicone mixture into them. We took our time with this step, pouring slowly to avoid introducing any new bubbles and to make sure the silicone filled every corner of the mold.

After carefully filling the molds with our silicone mixture, we set them aside to dry. Now it’s just a matter of waiting for the silicone to cure fully, so it can hold its shape and flexibility.

Once the silicone pieces were fully cured, we took the next step—gluing them together! We carefully applied silicone to bond the parts, making sure each side was aligned perfectly. After that, we set them aside to dry again, allowing the adhesive to cure completely.

Once the silicone mixtures were fully dried, we tested the molds by inflating them, and the results were fantastic! Each mold had its own unique way of expanding when air was blown into it, which was exactly what we hoped for. The flexibility of the materials, especially with the different silicone types, allowed for a wide range of movement and deformation, which is crucial for our soft robotics components. We were really pleased with how each piece responded to the air pressure—some expanded slowly, while others had more immediate reactions, adding a lot of character to each mold. You can see the different results below!

Experimenting with Vinyl and Tracing Paper Layers for Soft Robotics

For this phase of our soft robotics project, we experimented with layered vinyl and tracing paper to create flexible components that can be inflated. We used a straightforward shape in Illustrator to keep the design simple, which allows us to focus on observing the materials' interaction and flexibility.

Designing the Shape in Illustrator

Using Illustrator, I created a simple shape for testing. This minimalist design helps us clearly see how each material behaves without being affected by complex details.

Cutting Vinyl with the Roland Machine

To achieve precise cuts for each vinyl layer, we used the Roland vinyl cutter. Here’s the process we followed:

1. Load the Vinyl: We securely loaded the vinyl sheet into the Roland machine, making sure it was flat and properly aligned.
2. Set Up the Design: We adjusted the cut settings to match the vinyl’s thickness and texture.
3. Calibration and Test Cut: To ensure accuracy, we performed a test cut, allowing us to make any necessary adjustments before cutting the full design.
4. Final Cut: Once calibrated, the Roland machine cut the design precisely, producing clean edges on the vinyl that were perfect for layering.

Cutting Tracing Paper with the Laser Cutter

For the tracing paper, we used a laser cutter to achieve crisp, accurate cuts. This method allowed us to cut the delicate tracing paper cleanly without tearing or uneven edges.

Layering and Ironing Process

To build a structure suitable for inflation, we layered vinyl and tracing paper, bonding them with an ironing technique as follows:

1. First Layer - Vinyl: We began with a vinyl base layer, providing a strong, flexible foundation.
2. Second Layer - Tracing Paper: Next, we added tracing paper on top of the vinyl.
3. Third Layer - Vinyl: Finally, another vinyl layer was added on top to "sandwich" the tracing paper between two vinyl layers.

Ironing Process: Each layer was carefully ironed to ensure a secure bond without any trapped air pockets, which is essential for a smooth, airtight structure. Ironing the layers together helped fuse the vinyl and tracing paper, creating a flexible yet durable structure.

Preparing for Inflation

Once the layered structure was complete, we tested its flexibility and strength, which are key for soft robotics applications. By blowing air into the bonded layers, we observed how the structure expands and responds to pressure, achieving the desired movement and flexibility for our project.

Results

The combination of vinyl and tracing paper showed excellent potential for soft robotics. The structure held up well under inflation, expanding in controlled ways that we plan to explore further in upcoming designs.

Custom Silicone Shape for Soft Robotics

I created a custom silicone shape to explore flexibility and movement for soft robotics applications. Below are the steps I followed.

Designing the Shape in Illustrator

I began by designing a unique shape in Illustrator, suitable for inflation as a soft robotics component. My design required two molds:

• The Bottom Mold: This mold includes the pattern, allowing the shape to expand in specific areas when inflated.
• The Top Mold: This layer seals the shape, enabling it to hold air and be inflated.

Cutting the Layers with the Laser Cutter

Once the design was complete, I used a laser cutter to create each layer for the molds. The molds were made from five laser-cut acrylic layers:

1. The Bottom Layer
2. The Top Layer
3. The Pattern Layer – designed to control flexibility and movement during inflation.

To achieve precise cuts in acrylic, I used the following laser parameters:

• Speed: 12
• Minimum Power: 80
• Maximum Power: 85

These settings allowed me to cut cleanly through the acrylic, ensuring each layer fit perfectly during assembly.

Assembling the Molds

i carefully aligned and assembled the two main molds – the bottom mold with the pattern and the top cover – to create a secure mold for casting the silicone. This alignment is essential to ensure airtightness and proper shaping.

This is an experimental design, and I am excited to see how the structure performs when inflated. This process will give us insights into how mold designs influence the movement and flexibility of soft robotics components.

Filling the Molds with Silicone

After assembling the molds, I prepared 60 grams of silicone to fill them. However, I later realized that 60 grams was not enough to fill the entire mold properly. When I removed the silicone from the mold, I noticed it had gaps and was incomplete.

To address this, I tried again with 75 grams of silicone, which provided sufficient coverage for the mold, resulting in a complete and smooth silicone piece.

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This trial and error helped me understand the correct amount of silicone needed for this mold, ensuring better consistency in future casts.

Assembling the Soft Robot: Gluing and Final Preparations

For the final step of assembling my soft robotics design, I used silicone to glue the bottom and top layers together. I carefully applied 10 mg of silicone, which turned out to be just the right amount for this task! After evenly spreading it, I let it dry completely to ensure a strong bond. Once it was fully dried, the soft robotic structure was ready to inflate and test. ✨

And here, you can see below how it works! 🚀

Fabrication files

Vinyl and Tracing Paper Layers

Silicone Shape