8. Soft robotics

Research

Soft robotics is an emerging field focused on developing flexible, adaptable robots made from soft materials, such as silicone, gels, and polymers, rather than rigid metals or hard plastics. This week's exploration into soft robotics opened my eyes to the truly interdisciplinary nature of this field, bridging engineering, creative design, biology, and materials science.

These robots are designed to mimic the movement and adaptability of living organisms, allowing them to interact more naturally with their surroundings and handle fragile objects safely. Through research from Harvard's Soft Robotics and Soft Robotics at FAB24, I gained a deeper understanding of why soft robotics are needed and how they represent a paradigm shift from traditional rigid robotics.

Soft robotics has applications across many fields, from healthcare and environmental exploration to manufacturing and everyday life.

Key Characteristics of Soft Robotics¶

• Flexibility and Adaptability: Soft robots can bend, stretch, and deform, adapting to complex shapes and environments that would be challenging for traditional robots.

• Lightweight and Safe: Made from soft materials, these robots are often lightweight and pose minimal risk of injury, making them ideal for interacting with humans or handling delicate objects.

• Biomimicry: Many soft robotic designs are inspired by natural organisms, like octopuses, worms, or the human hand. These designs allow robots to move with high degrees of freedom and to perform tasks that require delicate precision.

• Air and Fluid Actuation: Soft robots commonly use air or fluid as actuators to create movement. These "pneumatic actuators" inflate and deflate parts of the robot, creating bending or stretching motion.

Applications of Soft

• Medical and Surgical Applications: Soft robots are used in minimally invasive surgeries, where their flexibility allows for precise, gentle interaction with organs and tissues. They’re also explored in prosthetics and assistive devices for improved comfort and adaptability.

• Industrial Applications: In manufacturing and packaging, soft robots are used to handle delicate items, like food or electronics, without damaging them.

• Exploration and Environmental Monitoring: Soft robots can explore challenging environments, such as deep-sea habitats, where their flexible bodies withstand pressure and complex terrain. They are also used in environmental monitoring to interact gently with plant and animal life.

• Wearable Robotics: Soft robotics are increasingly used in exoskeletons and wearable devices, providing support for people with limited mobility. These wearables help with physical rehabilitation by providing gentle assistance or resistance during movement.

Challenges in Soft Robotics¶

• Durability: Soft robots can be vulnerable to wear and tear, punctures, and environmental damage, limiting their lifespan and application.

• Complex Control Systems: Designing effective control systems for soft robotics is challenging due to the complexity of soft material dynamics and nonlinear motion.

• Precision: While soft robots are highly adaptable, achieving precise, repeatable movements is more complex than with rigid robots.

Future Directions¶

Soft robotics is a rapidly evolving field, with exciting research focusing on biohybrid systems that integrate living cells with synthetic materials, self-healing materials that can repair themselves, and new actuation methods that improve control and durability. The field is paving the way for robots that can seamlessly interact with humans, adapt to unpredictable environments, and open new possibilities for applications in healthcare, wearable technology, and sustainable solutions.

References & Inspiration

Key Research Resources:

Through my research, I explored several foundational resources that helped me understand the multidisciplinary nature of soft robotics:

• Soft Robotics at FAB24 - Comprehensive overview of soft robotics in the Fab Lab context
• Harvard's Soft Bots - Foundational research on soft robotic systems
• Fatemeh Mollaie's Soft Robotics Documentation - Excellent reference for documentation approach and process workflow

These resources helped me understand clearly what soft robotics are, why they're needed, and their interdisciplinary nature—spanning engineering, creative design, biology, and materials science. They demonstrated what is needed to make a soft robot and the various approaches to creating movement through pneumatic actuation.

Research Visual Gallery

Star-like Soft Robotic Inspiration

FAB Research Overview

BUET Electrified Project

Design Inspiration:

The star-down polygon-up robot design was inspired by natural organisms that use radial symmetry for movement and adaptation. The concept combines a star-shaped base (with soft arms or points) with a polygonal top (like a hexagon or pentagon)—imagine a soft starfish base holding up a flat polygon "cap." This structure creates interesting inflation patterns where air channels inside the star arms enable movement like crawling, gripping, or lifting.

Tools & Materials

• CorelDRAW - Design software for creating robot patterns
• Heat Press Machine - For sealing vinyl layers
• Silicone - Primary material for flexible robot body
• Vinyl - For layering and sealing structure
• Syringe - For inflating the robot structures
• 3D Modeling Software - For initial design and pattern development

Process and Workflow

Design Phase

I used CorelDRAW to design two different inflatable robot structures:

Robot Design Concepts

1. Pome/Apple Robot Attempt:

My initial goal was to create an inflated robot with a pome/apple structure featuring side leaves. However, during the design and fabrication process, I ended up creating something different—a design that resembles a modern calabash with a hand-like extension at the top right of the header tube. What I intended to be a simple leaf for the pome/apple structure evolved into an unexpected but interesting form.

2. Star-Down Polygon-Up Robot:

The second design features a star-shaped base (bottom) with soft arms or points, and a polygonal top (like a hexagon or pentagon). This structure is designed to inflate through air channels inside the star arms, with each chamber bending or expanding when filled with air—creating movements like crawling, gripping, or lifting.

Figure 1: Initial robot design patterns on paper

Fabrication Process

The fabrication involved several key steps:

1. Pattern Preparation: Transferred the CorelDRAW designs onto the materials
2. Layering: Combined silicone and vinyl layers to create the structure
3. Heat Pressing: Used the heat press machine to seal the layers together, creating air-tight chambers
4. Testing: Inflated the robots using a syringe to test the movement patterns

Unfortunately, I don't have images from when the first design failed—I forgot to capture that moment! However, the final redesigned versions came out successfully.

Fabrication Gallery

Heat Press Machine

Sealing Process

Final Inflatable Robot

Figure 2: Complete fabrication workflow from heat pressing to final robot structure

Inflation and Testing

Using a syringe, I tested the inflation patterns of both robot designs. The air flows through the internal channels, creating different movement patterns:

Testing Results

• Calabash-shaped Robot: The unexpected design created interesting inflation patterns with the hand-like extension responding to air pressure
• Star-Polygon Robot: The star arms expand and contract as air fills the chambers, demonstrating potential for crawling, gripping, or lifting movements

Digital Design to Physical Prototype

① Design Phase Initial design in CorelDRAW

② Export Phase Exported design as PDF

③ Print Phase Design loaded in printing software

Work in Progress

The star-polygon robot is still in the printing stage, and I will add final images once the fabrication is complete.

Inflation Test Video

🎥 Soft Robot Inflation Test
Demonstration of air flow and movement patterns through pneumatic actuation

Challenges and Learnings

Design Evolution

Design Challenge: Unexpected Results

The biggest challenge was that my initial pome/apple design didn't turn out as expected. Instead of creating a robot with side leaves, I ended up with a calabash-like structure with a hand extension. While this wasn't my original intention, it taught me valuable lessons about:

• The importance of precise pattern design in soft robotics
• How small design changes can lead to unexpected forms
• The iterative nature of soft robotics development
• Learning to embrace unexpected results and see their potential

Material Behavior

Key Learnings: Material Properties

Working with silicone and vinyl layers required careful attention to:

• Proper sealing to maintain air pressure
• Heat press temperature and timing for optimal bonding
• Layer alignment for functional air channels
• Material flexibility vs. structural integrity balance

Documentation

Lesson Learned: Capture Everything

I learned the importance of documenting failures—I forgot to capture images of the initial failed design, which would have been valuable for showing the complete design iteration process. This experience reinforced that every step matters, including the mistakes!

Reflections

This assignment opened my eyes to the interdisciplinary nature of soft robotics. The research from Harvard and FAB24 helped me understand:

Key Insights from This Project

Why soft robotics matter:

They offer safer human interaction, adaptability to complex environments, and biomimetic capabilities

The engineering challenges:

Balancing flexibility with functionality, creating effective air channels, and achieving predictable movement

The creative design aspect:

How biological inspiration translates into synthetic forms

The fabrication techniques:

Heat pressing, molding, and material layering

Working on inflatable robots combines engineering precision with creative problem-solving. While my first design didn't match my vision, the process taught me to iterate, adapt, and find value in unexpected outcomes—core principles of both soft robotics and the design process itself.

Documentation Status

Note: Star-polygon robot final images will be added once fabrication is complete.

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Acknowledgments

Special thanks to:

• Fatemeh Mollaie for providing excellent documentation reference and inspiration for structuring this assignment
• The Fabricademy instructors for guidance on soft robotics principles
• The lab team for assistance with heat press equipment and materials

References

1. Soft Robotics at FAB24 - Comprehensive soft robotics resources
2. Harvard's Soft Bots Research - Foundational academic research
3. Fatemeh Mollaie's Documentation - Process and workflow reference

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