Italian-Foam (I-FOAM) - 12.03.13
Science Objectives for Everyone
The Italian-Foam experiment will evaluate the recovery of shape memory epoxy foam in microgravity obtained by solid-state foaming on ground consisting of various geometric complexities shaped on ground. This investigation is expected to study the shape memory properties required to manufacture a new concept actuator (a device that transforms energy to other forms of energy).
Science Results for Everyone
University of Rome Tor Vergata, Department of Mechanical Engineering, Rome, , Italy
Kayser Italia Srl., Livorno, , Italy
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Italian Space Agency (ASI)Research Benefits
Information PendingISS Expedition Duration
March 2011 - September 2011Expeditions Assigned
27/28Previous ISS Missions
Increment 27/28 is the first scheduled ISS mission for Italian-FOAM investigation.
- The Italian-Foam experiment pertains to the recovery of shape memory epoxy foam produced on ground by a newly developed method known as solid-state foaming.
- The experiment will be performed utilizing foam samples consisting of various geometric complexities shaped on ground.
The Italian-FOAM experiment evaluates the recovery of shape memory epoxy foam in microgravity, which was obtained on ground consisting of various geometric complexities. Working shape memory polymers (SMPs) are based on the ability of these materials to fix a given deformation by cooling below a certain transition temperature (which is mostly the glass transition temperature). Upon reheating to above the transition temperature, the polymer chains reorganize, resulting in a macroscopic recovery of the original shape. Foaming is another way to tailor SMP properties for application requirements; foams generally have reduced mechanical stiffness and strength but enhanced compressibility. The Department of Mechanical Engineering of the University of Rome ?Tor Vergata? has developed a new foaming technology which is able to produce thermoset foams starting from thermosetting powders. This method is simpler than conventional foaming methods and gives homogeneous closed-cell foams with excellent mechanical properties. It was observed that foams produced by solid-state foaming present remarkable shape memory properties. In fact, these foams, which are very rigid at room temperature, become spongy when heated above the Tg (glass transition temperature); in this state they can be packed up to the complete collapse of the pores, without generating any foam damage. Cooling below transition temperature, this compact structure remains stable with no constraining force. When heated above the transition temperature, the foam recovers its original shape.
Italian-FOAM can be used in aerospace for different applications: from light actuators to structural parts with reduced size during shipping. In order to study the behavior of this new class of materials in microgravity, a set of experiments was designed for this mission. The shape recovery of an epoxy block, the unfolding of a complex structure, and a simplified actuator will be performed during the experiment, that will be carried out using a custom Experiment Unit placed on the Foam BIOKon Container (both developed by Kayser Italia). The hardware includes the heating system, data acquisition system, a battery pack, the control system, a sensor system to detect samples shape changes during heating time. The device is autonomous (not electrically connected with spacecraft). On-ground analysis of the retrieved samples will be performed in the PI?s lab and compared to samples tested in the same conditions on ground in order to investigate the behavior of this new class of materials in a microgravity environment.
Italian-FOAM can be used in the aerospace industry for different applications from light actuators to structural parts with reduced size during shipping. This type of foam may be very useful as a material utilized for building future spacecrafts for long-term space flight missions.Earth Applications
Italian-FOAM can be used as energy absorbers (panels and bumpers) and self expandable/deployable structures. Forms of foam are widely used in medical bedding and seating applications because of its unique attributes which can help aid comfort and sleep.
No crewmember observation is required. The device must be powered on by a crewmember during the on-orbit phase. The experiment will be executed automatically. All scientific data will be automatically stored by the device itself and processed on-ground. The device will be powered off by the crewmember, after about 60 minutes, at the end of experiment. The samples are required to return to ground for the postflight analysis.Operational Protocols
The Italian-FOAM/BIOKon container must be fixed to the middeck wall, with Velcro at the bottom. The samples will be inserted in an autonomous device, developed by Kayser Italia, contained in the standard BIOKon container and including a control and heating system, the battery pack and the experiment chamber with its data acquisition system. The container will remain stowed during the launch.
Experimental results onboard the ISS, along with results obtained on the ground, highlight the complexity in developing foams in microgravity for structural actuators. Foam heating system can behave very differently in space and heat fluctuation is greatly amplified by microgravity. In future experiments, the maximum temperature will increase (at least up to 120°C) if a heating plate will be used again. In the current experiment the maximum temperature was strongly reduced for safety reasons. Overall, good results were obtained and important information were acquired for defining a multi-functional composite structure for future experiments. Foam actuator made in space can be tested for compression, torsion, and flexure, but in the case of compression, attention has to be made to have a continuous contact between the foam walls and the heating walls during recovery. As a general conclusion, microgravity does not have much effect on the ability of the foams to recover the initial shape but strongly influences the behavior of the heating devices and, therefore, the efficiency of the foam recovery (Santo 2012)
Santo L, Quadrini F, Squeo EA, Dolce F, Mascetti G, Bertolotto D, Villadei W, Ganga PL, Zolesi V. Behavior of Shape Memory Epoxy Foams in Microgravity: Experimental Results of STS-134 Mission. Microgravity Science and Technology. 2012 September; 24(4): 287-296.
Santo L, Quadrini F, Mascetti G, Dolce F, Zolesi V. Mission STS-134: Results of shape memory foam experiment. Acta Astronautica. 2013 October; 91: 333-340. DOI: 10.1016/j.actaastro.2013.06.017.
Ground Based Results Publications
Artistic view of the Italian-Foam/BIOKon hardware. Image courtesy of ASI.
+ View Larger Image