Week 15 - Sardo

Introduction

Yeah 3D print with clay and special materials is cool, but Soft Robotic is way cooler.

Soft robotics is a subfield of robotics that concerns the design, control, and fabrication of robots composed of compliant materials, instead of rigid links. It is area in which robots, more specifically robotic actuators, are modeled based on how living organisms move and adapt to their surroundings. Rather than using rigid actuators and materials for robot design, using soft actuators provides an additional level of flexibility and adaptability of robotic manipulators. Soft robotic actuators are typically pneumatic actuators which perform movement or contraction when air within actuators is compressed.

There is still a lot of research in this field and about its purpose in the future. For now, you can see being vastly used in Automatic picking solution for Food and Goods

Case of use

Creating a Gripper

So, taking inspiration from the images above, I wanted to attempt making my onw gripper.

The process of making a Soft-Robotic Gripper involves a Silicon Casting of a kind of shape that when inflated it bends in specific directions.

In my case I took the mold directly from this model that I 3D printed.

3D model of the Mold

The model is composed of 3 parts:

The soft-robot shape
The complementary planar shape
The hole where insert the inflating tube

As you will follow this journey, I realized at the end that just the first part is enough to achive a good project.

Casting Attempts

For Casting I used Easy Plat 00-30 (datasheet).

Preparing the silicon

In the first attempt I casted both molds and then manually joined together with other silicon, the result did not end up being satisfing tho. The side layer was not strong enough to endure air pressure and on top of that the 2 shapes were very difficult to align manually.

First Attempt

Second attempt, to improve the alignment I proceded to cast just the first shape and then create a very thin layer on the base of the flat mold where after I put the first cast on top (as shown in the pic). This way I solved the alignment issue but the base layer ended up being to thin, fragile and not even.

Second Attempt

As a third attempt I finally used a piece of fabric as the basic layer, this way you also enforce the bendable movement in the proper direction considering the fabric is pretty rigid.

Anyway I want to warn to not press to much while you "glue" the cast on the fabric, otherwise you can end up clogging the air channel preventing the functioning.