8. Soft robotics¶
Research and Inspiration¶
As someone with a latex allergy, I’ve always had to find alternatives to standard latex balloons during family celebrations. We often used Mylar balloons instead, but even those come with limitations—mainly in terms of waste and single-use design. This personal challenge inspired me to explore the concept of reusable, inflatable forms using vinyl, a more durable and flexible material.
The goal was to design a sustainable, soft robotic structure—a balloon that could be inflated, deflated, stored, and reused multiple times—while also serving as a foundation for more complex inflatable costume elements like shoulder pads or wearable structures.
Workflow¶
Initial Attempt – Learning Through Failure¶
For the first prototype, I experimented with scrap vinyl material and attempted to heat-seal the edges using a standard clothing iron. Unfortunately, the heat was inconsistent, and the iron created uneven pressure, resulting in wrinkles and small leaks.
This trial taught me a key lesson: precision in pressure and heat application is critical when working with heat-sealable materials like vinyl. The process needed more control than the iron could offer, especially along the edges.
Step 1: Designing and Assembling the Balloon¶
To improve structural integrity, I switched to a hexagonal shape—a geometry that provides strength and visual interest. I cut two identical hexagon shapes from vinyl sheets and placed a layer of baking paper between them, leaving a 1 cm margin around the edges for sealing. The baking paper served as a barrier to prevent overheating during the press.
For sealing, I used a vinyl heat press, which provided consistent pressure and temperature, resulting in a strong, even bond. This method eliminated the issues from the earlier attempt, creating a smooth, airtight seal.
Step 2: Inflation and Deflation¶
To make the balloon functional, I added a small plastic straw into the seam during the sealing process. This acted as both the air inlet and outlet, allowing for easy inflation and deflation. Once sealed, the balloon could be used repeatedly and stored flat, making it practical and space-efficient. ...
Application: Inflatable Shoulder Pads¶
Design Concept¶
Building on the balloon concept, I developed inflatable shoulder pads designed specifically for cosplay and costume performance. These pads are not only lightweight but also adjustable in volume, allowing users to enhance certain body features (like shoulders, chest, or muscles) on demand.
Inside Design and Pattern Creation¶
The shoulder pad design was created freestyle, with a focus on internal airflow control. I added a “lift zone” within the pad—an interior area that inflates more than surrounding zones, strategically enhancing the silhouette of the wearer.
I drew the pad shapes by hand and carefully traced the air pathways onto the vinyl. These pathways acted like channels, guiding the air to specific regions for controlled inflation.
Pattern Tracing and Cutting¶
After cutting out the base shape, I traced the air/lift pathways onto the inside layer of vinyl to guide the inflation process effectively.
Heat Pressing¶
Using the same method as in previous projects, I heat-pressed the vinyl layers together to seal the edges, ensuring the structure could hold air without leaking.
Inflation¶
Once assembled, the shoulder pads were filled with air to test their functionality and confirm the design effectively enhanced the intended features.
Uses and Benefits¶
These inflatable shoulder pads are especially valuable for cosplayers, performers, and costume designers looking to add dramatic, dynamic features without the weight or permanence of foam or rigid inserts.
- Custom fit: Vinyl molds naturally to the body’s shape
- Concealable: Tubing can be hidden within costumes
- Reusability: Pads can be deflated, stored flat, and reinflated as needed
- On-the-go adjustments: Inflation level can be altered to suit the scene or outfit
This system enables on-demand body shaping, turning a simple costume into a transforming, interactive piece of wearable art.
Reflection¶
This project was an exciting exploration of soft robotics, sustainable design, and wearable innovation. The development of a reusable balloon from vinyl addressed a personal need, but it also opened doors to broader applications in fashion, cosplay, and performance.
The failed first attempt reinforced the value of experimentation and the importance of using the right tools for precision work. The shift from iron to a proper heat press made all the difference in achieving clean, airtight seals.
Overall, the combination of design flexibility, eco-conscious materials, and functionality resulted in a versatile, scalable method for creating soft, inflatable elements with a wide range of uses.
Experiment 2 – Silicone Shoulder Pad Molded Over a Balloon¶
Concept and Purpose
In contrast to the inflatable vinyl structure, this second experiment explores creating a soft, durable shoulder pad using silicone casting. Inspired by organic muscle contours and armor-like shapes often found in creature or fantasy costume design, this method uses a balloon as a temporary, inflatable mold base. The balloon provides a smooth, curved form that can be manipulated before the silicone cures, allowing for a customizable, soft robotic shape.
This process focuses on form memory and pliability—creating a shoulder structure that keeps its form but remains flexible enough for comfort and movement. I chose Etter Art’s two-step silicone for its skin-safe formulation and good flexibility.
Materials Used¶
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Etter Art 2-Part Silicone (Platinum cure)
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Balloon (non-latex, due to allergy)
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Petroleum jelly or mold release spray
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Mixing cups and stir sticks
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Nitrile gloves
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Duct tape (to help shape balloon)
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Scissors
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Optional: Fabric mesh or tulle for reinforcement layer
Step 1: Preparing the Mold Base¶
I inflated a balloon to approximately shoulder size and adjusted its shape using duct tape—taping down parts of the balloon to create a more anatomical shoulder curve. The goal was to simulate the muscle slope and give structure to the final piece. I placed the balloon inside a shallow cardboard box to keep it stable during the casting process.
To prevent sticking, I lightly coated the balloon in a layer of mold release agent.
Step 2: First Silicone Layer – Skin Coat¶
I mixed the two parts of the Etter Art silicone and applied the first thin layer by brushing it directly onto the balloon surface. This layer captured the surface details and served as a "skin coat" to ensure full coverage.
This layer was left to partially cure until it reached a tacky consistency.
Step 3: Second Silicone Layer – Bulk and Reinforcement¶
Once the first layer was tacky, I mixed another batch of silicone and applied it more generously to build volume. Optional: I embedded a thin piece of tulle or fabric mesh into this layer to increase tear resistance and structural strength without compromising flexibility.
This second layer was shaped by hand to reinforce volume in specific areas—particularly along the top ridge of the shoulder pad, to create a lifted profile like a costume pauldron or muscle enhancement.
Step 4: Curing and Removal¶
After the full curing time (as specified by the silicone product), I carefully deflated the balloon. The silicone shell detached cleanly, leaving behind a hollow, lightweight form that held the shoulder contour. Despite being soft, the shape retained its structure well.
Result and Applications¶
The resulting silicone shoulder pad was soft, form-fitting, and reusable. It flexes naturally with body movement and could be worn under or over costume fabric for a muscle-enhancing or armor-like effect. The inside surface conformed well to body curves, and the outer surface was smooth, making it easy to paint, attach, or embed with other costume elements (like LEDs or textiles).
Benefits and Observations¶
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No seams: Since the silicone was poured in one piece, the final product has a clean, organic look
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Reusable mold shape: Balloons of different sizes and shapes can be used to create custom forms
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Soft yet structured: A perfect balance for wearable comfort and visual volume
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Latex-free process: Safe for users with latex sensitivities
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Expandable method: Can be scaled up for other body parts—chest plates, back armor, thigh padding
Reflection¶
This second experiment offered a great contrast to the vinyl heat-sealing approach. While the first method allows for inflatable, adjustable elements, this silicone technique creates semi-permanent, body-conforming pieces ideal for repeated wear. Both have unique strengths in wearable design and could even be combined in future hybrid prototypes.