Soft Actuator Fabrication

Overview of the project

During my time at the HKUST Robotics Institute, I got interested in the soft actuators projects under professor Michael Yu Wang. I discussed with the Ph.D and M.Phil Students and decided to try a develop a different method for manufacturing soft actuators with complex internal structures.

I used my specialty in 3D printing and decided to use water solvable PVA in building the internal molds in the molding process .

The Project is still at an very early age and some pictures displaying the current progress can be found below:

Test actuator, Test Mold, PVA Water Solvable Mold

I designed a set of molds, including internal mold and external mold, to be printed in PVA, which is a water solvable material commonly used for support in 3D printing. with this design, complex internal structures can be achieved with a single molding operation as the internal mold can be dissolved and no special design compensations for mold detachment is needed.

This is superior comparing with the common practice:

1. Better structural strength comparing with molding method to use multiple molding operations each shaping part of the internal structure, as there's no danger of pollution and detachment at the intersections between different mold operations.

2. Better performance than 3D print methods (typically with TPU) in high pressure applications as the molded part have better structural integrity.

Below are some pictures of the test actuator

Top View - Unpressurized

Top View - Pressurized

Side View - Unpressurized

Side View - Pressurized