Foam actuators are a type of soft actuator that were originally developed in the Organic Robotics Lab at Cornell University. They are composed of an open-celled elastomer foam which is sealed with a nonporous elastomer.
The main advantage of these actuators is that they can easily be cast, cut, and even sculpted into 3D shapes, allowing simple fabrication of 3D soft machines. Examples of foam shapes are shown in the figure below.
Open channels and chambers for inflation are a requirement for fluidic actuators. Using other fluidic actuator fabrication methods often requires either difficult molding methods (such as lost wax casting) or complex assemblies of small actuators to form these channels. With foam actuators, the fluidic channels are already present in the form of the interconnected pore network.