Extremely compact and fast actuators based on shape-memory alloys
Actuators based on thermal shape memory alloys (SMA) boast the highest energy density of all actuators presently available. They are capable of generating high forces in a small space, and the structural change generated by temperature change can be used to switch the actuator. While heat in the actuator can be increased with little effort, quick cooling presents a particular challenge.
As part of the HochPerForm project, Fraunhofer IPM is working with other Fraunhofer institutes to find a solution to this challenge. One possibility is cooling via latent heat, as used in heat pipes, for example. However, to prevent a permanent heat flow from the actuator to the cold side, a switching mechanism must also be integrated into the heat pipe.
The overall aim is to improve the cooling rate and thus the operating frequency of the SM actuators by a factor of 100 by means of a heat transfer process based on evaporation and condensation and by using generative manufacturing processes. The resulting actuator systems shall combine extremely high energy density with switching frequencies of more than one hertz in a minimum of space.
Project partners
- Fraunhofer Institute for Machine Tools and Forming Technology IWU (project coordination)
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM
Project funding
Fraunhofer Prepare program
Project term
March 2020 to February 2023