Ryuma Niiyama, Lining Yao, Hiroshi Ishii

Abstract

This paper presents a weight-changing device based on the transfer of mass. We chose liquid metal (Ga-In-Tin eutectic) and a bi-directional pump to control the mass that is injected into or removed from a target object. The liquid metal has a density of 6.44g/cm3, which is about six times heavier than water, and is thus suitable for effective mass transfer. We also combine the device with a dynamic volume-changing function to achieve programmable mass and volume at the same time. We explore three potential applications enabled by weight-changing devices: density simulation of different materials, miniature representation of planets with scaled size and mass, and motion control by changing gravity force. This technique opens up a new design space in human-computer interactions.