8. Soft robotics

Research and Ideation

Soft robotics is a field of robotics that focuses on creating robots made from flexible, deformable materials, often inspired by the way biological organisms move and function. Unlike traditional rigid robots with hard frames, soft robots are designed to bend, stretch, twist, and compress, allowing them to adapt to their environment in a more versatile and human-like way.

Soft robotics is a field of robotics that focuses on creating robots made from flexible, deformable materials, often inspired by the way biological organisms move and function. Unlike traditional rigid robots with hard frames, soft robots are designed to bend, stretch, twist, and compress, allowing them to adapt to their environment in a more versatile and human-like way.

Characteristics of soft robotics

• Flexibility and Adaptability: Soft robots can bend, stretch, and change shape to conform to complex environments where traditional robots would struggle.
• Lightweight and Safe: Constructed from soft materials, these robots are lightweight and pose minimal risk of injury, making them ideal for interacting with humans and handling delicate objects.
• Biomimicry: Inspired by nature, soft robots mimic the movements of organisms like octopuses, worms, and human hands, allowing for greater flexibility and precision in tasks requiring delicate handling.
• Air and Fluid Actuation: Soft robots often use pneumatic or hydraulic actuators, where air or liquid is pumped to create movement, enabling controlled bending and stretching.

Applications of soft robotics

• Medical and Surgical Uses: Soft robots are employed in minimally invasive surgeries due to their flexibility, allowing for precise interactions with organs and tissues. They are also used in prosthetics and assistive devices for enhanced comfort and adaptability.
• Industrial Applications: In manufacturing and packaging, soft robots handle fragile items, such as food and electronics, without causing damage.
• Exploration and Environmental Monitoring: Soft robots are used in challenging environments, such as deep-sea habitats, where their flexibility helps them withstand extreme pressures and navigate rough terrain. They are also valuable for environmental monitoring, as they can interact gently with plant and animal life.
• Wearable Robotics: Increasingly integrated into exoskeletons and assistive wearables, soft robotics support individuals with mobility impairments and aid in physical rehabilitation by providing controlled assistance or resistance.

Challenges in soft robotics

• Durability: Soft robots are susceptible to wear, punctures, and environmental damage, which can limit their lifespan and effectiveness.
• Complex Control Systems: The dynamic behavior of soft materials makes designing precise control mechanisms more challenging than in rigid robotics.
• Precision: Although highly adaptable, soft robots struggle with achieving consistent, repeatable movements compared to their rigid counterparts.

Future directions

Soft robotics is advancing rapidly, with ongoing research focusing on biohybrid systems that integrate living cells with synthetic materials, self-healing materials that repair damage, and innovative actuation methods to improve movement and durability. These advancements will enable robots to interact more seamlessly with humans, adapt to unpredictable environments, and expand their applications in healthcare, wearable technology, and sustainable solutions. I was particularly impressed by the work of MotorSkins. They focus on textiles integrated with fluidic systems for human-machine interaction. One of their standout products is a dynamic massage garment that gently compresses the calf muscles during walking. This intermittent compression has been proven to enhance circulation, reduce oedema, speed up recovery post-sports, and even help prevent deep vein thrombosis.

Inspirations

Basic inflatables Vinyl experiment

This week, we engaged in a hands-on exploration of inflatable structures using vinyl and laser-cut No fire paper. Through this process, we examined the basics of air channel design and how careful planning impacts the movement and form of soft robotic components.

Materials required

1. Two sheets of heat press vinyl
2. Laser-cut baking paper
3. Vinyl cutter
4. Heat press machine
5. Air pump or syringe
6. Scissors (optional for edge refinement)

Once I gather all my materials, I use an iron to fuse them together since the experiment is small. The vinyl consists of two layers: a soft outer layer that doesn’t stick and an adhesive layer that holds the baking paper in place when heated. The purpose of the baking paper is to create non-stick areas so that when the structure is inflated, air can flow through easily.

Cover the baking paper with Vinyl on both the side. Make sure the size towards paper are correct before proceeding for sealing.

Final result

Fabrication file

Down here there is a file for my inflatable design

Inflatable design file

Soft Robotic with Gelatin

Soft robotics with gelatin explores the use of biodegradable, flexible, and food-safe materials as an alternative to traditional silicone-based actuators. In my experimentation, I used gelatin to create a soft robotic structure, uncertain at first whether it could match the elasticity and strength of silicone. The process involved melting and molding gelatin into a desired shape, then testing its ability to expand and contract under air pressure.

Although I had doubts about its durability and performance, the final outcome was surprisingly successful. The gelatin structure demonstrated enough flexibility and responsiveness to function as a soft actuator. This work was inspired by researchers like Elissa Ross and teams at institutions such as Harvard’s Wyss Institute, where soft robotics is being advanced using edible and biodegradable materials for eco-friendly and medical applications. Their innovations motivated me to explore gelatin not just as a kitchen ingredient, but as a serious material in sustainable robotics.

Ingredients used

Ingredient	Amount Used	Purpose/Function
Gelatin	15 grams	Main structural material for the soft actuator
Water	100 ml	Solvent to dissolve and activate the gelatin
Glycerine	1 tablespoon	Acts as a plasticizer to increase flexibility
Black Tea	50 ml (brewed)	Natural dye to give color to the soft robot

Tools

Tool	Purpose/Function
Kettle	For heating water used to dissolve the gelatin
Spoon or Stirring Stick	To stir the mixture while combining ingredients
Measuring Cups/Spoons	For accurately measuring ingredients like glycerine and gelatin
Measuring Jug	To measure and pour hot water safely
Straw	Used to create air channels or hollow parts in the soft robot
Small Plate	As a base to hold or pour the gelatin mixture for shaping and cooling

Procedures

STEP 1: Prepare the Colored Water

Boil a small amount of water in a kettle. Once boiled, pour about 100 ml into a measuring jug, then add a small amount of black tea (or any natural tea) to infuse color into the water. Let it sit for a few minutes, then strain out the tea leaves if needed.

STEP 2: Measure and Mix Ingredients

In a small bowl or jug, add:

     * 10 grams of gelatin

     * 2 tablespoons of glycerine

Pour in the colored hot water gradually while stirring with a spoon or stirring stick. Continue stirring until everything is fully dissolved and no lumps remain.

STEP 3: Pour the Mixture

Take a small plate and pour the mixture onto it. The plate will serve as your base, allowing the mixture to spread out in a thin layer. This helps in forming a soft, flexible sheet.

STEP 4: Add Air Channel

Before the mixture starts to set, gently insert a straw into one side of the poured gelatin sheet to create a small air channel. This simulates a soft robotic actuator design.

STEP 5: Let It Set

Leave the plate at room temperature for 12–24 hours to allow the mixture to cool and harden into a rubber-like texture. You can speed up the process by placing it in a ventilated space.

STEP 6: Test the Soft Robot

Once fully set, you can try blowing air gently through the straw to see how the soft gelatin structure reacts. It should expand slightly or bend, depending on your design.

The result

The result of the experiment was a soft, heart-shaped gelatin structure that turned out surprisingly well. Its smooth, translucent texture and light brown tint from the tea gave it an organic and natural appearance. The shape held firmly, yet remained flexible to the touch, and the added straw allowed for gentle inflation, mimicking the basic movement of a soft robotic actuator. The aesthetic heart design not only looked appealing but also proved that gelatin could serve as a biodegradable alternative to silicone in soft robotics.

Robot Gripper with three fingers for Chess Robot

🛠️ Extra Content

Note: Although this gripper is not a soft robot, I’ve included it here because it could still be useful for anyone exploring soft grippers in the future. The project focuses on gentle handling using flexible parts and a simple mechanism, which might inspire ideas or serve as a technical reference when developing soft robotic grippers later on. So even though it’s not part of the soft robotics module, I thought it was worth sharing!

Introduction

This gripper has been specifically developed for integration into a Chess Robot project. It is powered by a micro servo motor, which controls a set of 3D-printed gears working in tandem with flexible, soft components. These elements work together to replicate a pinching motion, allowing the gripper to grasp and lift chess pieces with precision. The design ensures a balance between gentle handling and a secure grip, minimizing the risk of damaging or dropping the pieces during movement.

The gripper uses one Hobbyking TurnigyTG9e Analog Micro Servo with 1.5kg/cm (4.8V) of Torque. All parts were 3D printed in PLA and assembled with M2.5 screws (Various sizes needed). All parts can be printed with out support. The GripperFinger.stl includes some built in support that can be easily removed with a cutter after printing.

Files

1. Gripper Arm

2. Gripper Articulation 1

3. Gripper Articulation 2

4. GrippeR Finger

5. Gripper HexBase

6. Gripper ServoDisk

7. Assembly

Purpose and Motivation

• To explore how soft robotics and actuation mechanisms can be applied in assistive devices or automated systems.

• To create a low-cost, customizable gripper that can be used in vending robots, automated drink dispensers, or even prosthetic tools.

• To experiment with combining rigid and soft structures for better adaptability and functionality.

Materials and components

Material/Component	Use
Tower Pro SG90 Micro Servo Motor	Powers the gripper's pinching mechanism by rotating the gear system.
3D-printed gear system and frame (PLA)	Forms the structure of the gripper and transmits motion from the motor.
Arduino Uno	Acts as the microcontroller to control the servo motor.
Jumper wires and breadboard	Used for prototyping and connecting components without soldering.
Power source (USB)	Supplies power to the Arduino and servo motor.
Fasteners	Secures components in place to ensure stability.

Procedure: Building a Chess Robot Gripper System

Step 1: 3D Print the Gripper Components

• Download or design a gripper model (consisting of the frame and gears).
• Use PLA filament to 3D-print the parts.
• Ensure all gears and joints fit together smoothly.

Step 2: Assemble the Gripper Mechanism

• Attach the gears to the gripper arms and mount them onto the 3D-printed frame.
• Fix the micro servo (Tower Pro SG90) in its designated slot.
• Connect the servo horn to the gear system so that its rotation triggers the pinching motion.

Step 3: Prepare the Soft Grip Material

• Cut a plastic bottle or other soft, flexible material into appropriate pieces.
• Attach these to the inner surfaces of the gripper arms to create a gentle, non-slip surface.
• Use hot glue or fasteners to secure the soft components.

Step 4: Set Up the Electronics

• Mount the Arduino Uno onto a breadboard or baseboard.

• Connect the servo motor to the Arduino:

• Signal (Orange) wire to Digital Pin 9

• VCC (Red) wire to 5V
• GND (Brown/Black) wire to GND
• Connect the USB cable to the Arduino and your computer for programming and power.

Step 5: Upload the Servo Control Code

• Open the Arduino IDE and use this sample code:

#include <Servo.h>

Servo myServo;  // Create servo object

void setup() {
  myServo.attach(7);      // Attach servo to digital pin 7
  myServo.write(180);     // Immediately set to 150 degrees
  Serial.begin(9600);
  Serial.println("Servo set to 150°");
}

void loop() {
for(int i=160;i>=40;i--){
  myServo.write(i);
  delay(10);
}

delay(15000);

for(int i=40;i<=160;i++){
  myServo.write(i);
  delay(10);
}

delay(15000);

}

Code used

• Upload the code to the Arduino.
• Adjust angles (0 and 90) to fine-tune open/close positions based on your gear setup.

Step 6: Test the Gripper

• Run the Arduino code and observe the gripper’s motion.
• Make sure it opens and closes smoothly.
• Test it by picking up different chess pieces to ensure gentle and secure gripping.

Step 7: Final Assembly and Calibration

• Secure all components onto the robot’s base or arm.
• Make final mechanical adjustments for alignment.
• If part of a full Chess Robot, integrate the gripper into the robotic arm system and coordinate it with piece-detection logic.

Potential applications

Application Area	Description
Chess-Playing Robots	Automates physical chess games by picking up and moving pieces on the board with high accuracy.
Educational Robotics	Serves as a hands-on learning tool for teaching programming, electronics, and mechanical design.
Small Object Manipulation	Useful for robots that need to handle delicate or tiny objects, such as beads, screws, or components.
Assembly Line Robotics	Can be adapted for low-cost automation in lightweight manufacturing tasks or electronics assembly.
Service Robotics	Enables assistive robots to interact with small objects like medication bottles or utensils.
Prosthetics Research	Inspires gripper designs in low-cost prosthetic limbs, emphasizing soft gripping with precision.
DIY & Hobby Projects	Ideal for makers building robotic arms or toys requiring object interaction.
Warehouse Micro-Picking	Could be integrated into small-scale logistics robots for sorting lightweight items.

Result

Reflection on the Chess Robot Gripper Project

Building the Chess Robot Gripper was a hands-on learning experience that combined mechanical design, electronics, and programming into a compact, functional system. Through this project, I deepened my understanding of how servo motors and gear mechanisms work together to produce precise, controlled motion. The integration of soft materials for gripping taught me the importance of balancing functionality with care—especially when dealing with fragile or lightweight objects like chess pieces.

Using 3D-printed components offered flexibility in prototyping and encouraged iterative design, while working with the Arduino platform made coding and testing accessible and straightforward. One key takeaway was the importance of alignment and calibration—small mechanical misalignments could lead to big performance issues.

Overall, the project demonstrated how simple materials and affordable technology can be combined to create an intelligent, task-specific robotic system. It also sparked ideas for broader applications beyond chess, such as in automation, assistive technology, and educational robotics.

To enhance the aesthetic appeal of my Chess Robot Gripper, I decided to crochet small gloves to cover the gripping ends. While the mechanical design and functionality were my primary focus, I realized that integrating handmade elements could add a personal, visually pleasing touch to the project. The crocheted gloves not only made the gripper look softer and more inviting but also contributed to a gentler grip—especially useful when handling delicate chess pieces. This blend of robotics and textile craftsmanship reflected my desire to merge technical precision with creative expression.