1. Introducing Pneumatic 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_orange.svg" alt="/icons/exclamation-mark-double_orange.svg" width="40px" /> Making a pressurized flexible actuator deform into a desired shape and exert force is a challenge!

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