LiftTiles: Constructive Building Blocks for Prototyping Roomscale Shapechanging Interfaces. Largescale shapechanging interfaces have great potential, but creating such systems requires substantial time, cost, space, and efforts, which hinders the research community to explore interactions beyond the scale of human hands. We introduce modular inflatable actuators as building blocks for prototyping roomscale shapechanging interfaces. Each actuator can change its height from 15cm to 150cm, actuated and controlled by air pressure. Each unit is lowcost (8 USD), lightweight (10 kg), compact (15 cm), and robust, making it wellsuited for prototyping roomscale shape transformations. Moreover, our modular and reconfigurable design allows researchers and designers to quickly construct different geometries and to explore various applications. This paper contributes to the design and implementation of highly extendable inflatable actuators, and demonstrates a range of scenarios that can leverage this modular building block.

Modular Volumetric Actuators Using Motorized Auxetics Volume change has become a critical actuation method in robotics. However, the need for fluid flow or thermal processes to generate volume changes limits the durability, speed, and efficiency of these actuators. In this paper, we develop a new electromechanical actuator that volumetrically expands. By combining auxetic materials with a servo, we produce a simple isotropically expanding actuator that can be modularly composed. We discuss the symmetry considerations in selecting an appropriate auxetic framework for our actuator, eventually choosing a doublelayered polyhedral auxetic design. Characterization shows that a single actuator can expand in radius to 119% of the original size and generate 90N of force, while maintaining a small package and a speedy expansion  contraction cycle. Finally, we demonstrate the modularity of our actuators by linking three actuators to create a vertical tubecrawling robot. The small package and fast cycle time of our system highlight how viable these electromechanical volumetric actuators can be as an important actuator modality.