The challenge of upscaling paraffin wax actuators
Arne Mann, Thiemo Germann, Mats Ruiter, Peter Groche
Abstract
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 struggle with these demands. A new and efficient actuator concept for establishing closed-loop control circuits is needed. This article presents a new actuator 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 in manufacturing are discussed. A possible application is demonstrated by a thermal compensation element activated by energy from the surroundings.