Part 1. Introducing Soft Fluidic Actuators

Conventional fluidic actuators (both hydraulic and pneumatic actuators) use hollow cylinders with inserted pistons, and they are among the most common actuators in our daily lives:

• Their working principles and designs are simple and straightforward.
• They have exceptionally high power density.
• They are both reliable and easy to maintain.
• …

[Image Adapted from K. Suzumori et al. (2023) The Science of Soft Robots]

Pressure ( $P$ ) and flow rate ( $Q$ ) are often used to evaluate the power driving a fluidic actuator.

If we replace the rigid cylinder and piston with a compliant chamber, could we create a flexible fluidic actuator that inherits these advantages, like the conceptual drawing below?

[Image Adapted from K. Suzumori et al. (2023) The Science of Soft Robots]

Unfortunately, it's not that straightforward—these flexible chambers naturally want to inflate into spherical balloons!

<aside> <img src="/icons/exclamation-mark-double_gray.svg" alt="/icons/exclamation-mark-double_gray.svg" width="40px" /> Making a pressurized flexible actuator deform into a desired shape and exert force is a challenge!

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