The challenge of upscaling paraffin wax actuators

Higher levels of automation necessitate active spacer and adjusting elements generating high stroke forces. For these, the multitude of applications inside a manufacturing system requires a space- and cost-effective design. Conventional actuator concepts strugglewith these demands. A new and efficient actuator concept for establishing closed-loop control circuits is needed. This article presents a newactuator concept, based on the phase change material paraffin wax. Although paraffin wax actuators are a convenient solution for microactuators, high force macroscopic actuators are not established yet. On a macroscopic scale the design of the actuator housing and the manufacturing process are challenging. The presented concept consists of a closed housing, which surrounds the phase change material. A compact actuator design without sealed moveable parts is realized. Thus, the actuators provide high axial forces. Compared to existing solutions an increase in performance by a factor of 7 could be achieved. The essential actuator structure is introduced, characterized and the challenges inmanufacturing are discussed. A possible application is demonstrated by a thermal compensation element activated by energy from the surroundings.