Fraunhofer IAP: Shaped polymer reduces the weight of satellite hinges by 93 percent

Thermally induced movement in the component

The polymers are first formed into a temporary shape and retain this shape after thermomechanical programming. Upon heating, they revert to their original shape due to the one-way shape memory effect. This allows the mechanism to unfolding the solar panels to be integrated immediately into the component. HDRMs secure the panels during satellite launch and discharge them after thermal activation; the hinges then take over the deployment.

to additive manufacturing, the Fraunhofer IAP processed the polymers into printing filaments. Under controlled laboratory conditions, a hinge unfolded when heated from 23 to 140 degrees Celsius within 60 seconds. 3D printing a hinge or an HDRM takes about 15 minutes each; the subsequent programming takes approximately 30 minutes. In one 4D printing variant, the motion function is programmed during the printing process. In this way, HDRMs can be generated in about five minutes without a separate programming measure.

Hinges made of shape-memory polymers enable the deployment of solar panels. The motion function is integrated immediately into the additively manufactured components – (Image: Fraunhofer IAP / Jadwiga Galties). Hinges made of shape-memory polymers enable the deployment of solar panels. The motion function is immediately integrated into the additively manufactured components – (Image: Fraunhofer IAP / Jadwiga Galties). Project partners are developing solar panel substrates and electronics.

In addition to the Fraunhofer IAP, Orion Additive Manufacturing GmbH, German Orbital Systems GmbH, and the Fraunhofer Institute to Reliability and Microintegration IZM were involved. Orion developed a printing system to continuous carbon-fiber-reinforced polyetheretherketone (PEEK) and manufactured solar panel substrates to a 1U CubeSat from a laser-structurable PEEK material. The Fraunhofer IZM fabricated electrical conductive traces on the three-dimensional substrates using laser direct structuring and metallization, populated them with electronic components, and evaluated their reliability through vibration and thermal shock tests, among other methods. German Orbital Systems took over PCB design, electronics and heating elements, as well as system integration and functional testing.

Hold-Down-and-discharge Mechanisms (HDRMs) made of shape-memory polymer securely hold components in place during launch and discharge them precisely in orbit – (Image: Fraunhofer IAP / Jadwiga Galties). Hold-Down-and-discharge Mechanisms (HDRMs) made of shape-memory polymer securely hold components in place during launch and discharge them precisely in orbit – (Image: Fraunhofer IAP / Jadwiga Galties). Laboratory tests completed, space qualification pending

The hinges and locking and discharge mechanisms were tested under cleanroom conditions, during temperature cycling, and in initial vacuum tests. One of the developed shape-memory polymers also passed a outgassing test at the Spanish Instituto Nacional de Técnica Aeroespacial (INTA). To date, no testing under actual space conditions has been conducted. German Orbital Systems has expressed interest in conducting similar experiments as part of a follow-up project; discussions are currently underway.

The project, carried out from October 2023 to September 2026, was funded by the Investment Bank of the State of Brandenburg with co-financing from the European Union, as well as by the Berlin Investment Bank. The Fraunhofer IAP will present its developments at Formnext 2026 in Frankfurt am Main, at the Fraunhofer Competence Field to Additive Manufacturing booth, and at Space Tech Expo Europe in Bremen.

Formnext 2026, Frankfurt am Main, 17th-20th November 2026, Hall 11.0, Booth D31