Self-Healing Materials Systems: Overview of Major Approaches and Recent Developed Technologies

The development of self-healing materials is now being considered for real engineering applications. Over the past few decades, there has been a huge interest in materials that can self-heal, as this property can increase materials lifetime, reduce replacement costs, and improve product safety. Self-healing systems can be made from a variety of polymers and metallic materials. This paper reviews the main technologies currently being developed, particularly on the thermosetting composite polymeric systems. An overview of various self-healing concepts over the past decade is then presented. Finally, a perspective on future self-healing approaches using this biomimetic technique is offered. The intention is to stimulate debate and reinforce the importance of a multidisciplinary approach in this exciting field

Micromechanical characterization of single-walled carbon nanotube reinforced ethylidene norbornene nanocomposites for self-healing applications

We report on the fabrication of self healing nanocomposite materials, consisting of single-walled carbon nanotube (SWCNT) reinforced 5-Ethylidene-2-norbornene (5E2N) healing agent -reacted with Ruthenium Grubbs catalyst- by means of ultrasonication, followed by a three-roll mixing mill process. The kinetics of the 5E2N ring opening metathesis polymerization (ROMP) was studied as a function of the reaction temperature and the SWCNT loads. Our results demonstrated that the ROMP reaction still effective in a large temperature domain (-15 to 45 ºC), occurring at very short time scales (less than one minute at 40 ºC). On the other hand, the micro-indentation analysis performed on the SWCNT/5E2N nanocomposite materials after its ROMP polymerization were shown a clear increase in both the hardness and the Young modulus -up to nine times higher than that of the virgin polymer- when SWCNT loads range only from 0.1 to 2 wt. %. This approach demonstrated here opens new prospects for using carbon nanotube and healing agent nanocomposite materials for self-repair functionality, especially in space environment

Fluidic patch antenna based on liquid metal alloy/single-wall carbon-nanotubes operating at the S-band frequency

This letter describes the fabrication and characterization of a fluidic patch antenna operating at the S-band frequency (4GHz). The antenna prototype is composed of a nanocomposite material made by a liquid metal alloy (eutectic gallium indium) blended with single-wall carbon-nanotube (SWNTs). The nanocomposite is then enclosed in a polymeric substrate by employing the UV-assisted direct-writing technology. The fluidic antennas specimens feature excellent performances, in perfect agreement with simulations, showing an increase in the electrical conductivity and reflection coefficient with respect to the SWNTs concentration. The effect of the SWNTs on the long-term stability of antenna’s mechanical properties is also demonstrated

Stability of hydrated minerals on Mars

The validity of recent identification of various hydrated minerals (kieserite, gypsum, hexahydrite, nontronite, chamosite, and montmorillonite) on Mars was assessed by exposing these minerals to simulated Martian surface conditions of atmospheric composition and pressure, temperature, and ultraviolet light irradiation. When exposed to such conditions the hydrated minerals exhibit in general, greater losses of interlayer H2O than structural OH. Minerals such as gypsum that contain structural H2O are more resistant to H2O loss than phyllosilicates. The partial loss of OH in some of the phyllosilicates is not accompanied by a measurable and systematic change in the wavelength position or intensity of metal-OH absorption bands. The characteristic absorption features that allow for identification of these minerals on Mars may be reduced in intensity, but are nevertheless largely preserved.This study was supported with grants from the University of Winnipeg, the Canadian Space Agency. Funding for our spectrometer and Mars environment chamber facility at the University of Winnipeg (HOSERLab) was provided by the Canada Foundation for Innovation, the Manitoba Research and Innovation Fund and the Canadian Space Agency.https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2007GL03126

Project MoonDust: Characterization and Mitigation of Lunar Dust

The feasibility of extended exploration and human presence on the Moon and Mars depends critically on dealing with the environmental factors, especially the intrusive effects of dust. The prior Apollo landed missions found that the lunar dust exhibited high adherence to exposed surfaces and a restrictive friction-like action causing premature wear of the EVA suits. MoonDust is a project being performed in collaboration with the Canadian Space Agency to study the effects of lunar dust on optics and mechanics, and to develop innovative solutions to extend their operational lifetime within a lunar or Mars environment based on the unique properties of carbon nanotube (CNT) nanocomposites. To assist this work, a small lunar environment simulation vacuum chamber has been set-up at MPB Communications to enable the study of lunar dust effects on optics and rotary mechanisms at pressures to below 10-5 Torr. New lunar dust simulants have been developed at the University of Winnipeg, characteristic of lunar Mare (UW-M1) and highland (UW-H1) compositions, that incorporate nanophase Fe in the silica particles. This paper describes the preliminary characterization of the various available lunar dust simulants that has included IR Raman for composition, Atomic Force and SEM Microscopy for morphology, and Vibrating Sample Magnetometer (VSM) for magnetic properties. Trial CNT dust deflectors/traps were fabricated and experimentally validated for magnetic and electrostatic interactions with lunar dust simulants. Good deflection and retention of submicron dust particles for device dust protection was observed. The preliminary experimental results are discussed

Fibre bragg gratings in harsh and space environments: principles and applications

This book addresses the critical challenge of developing Fibre Bragg Gratings (FBGs) for applications as sensors in harsh and space environment. Coverage ranges from the basic principles through design, fabrication, and testing to their industrial implementation

Moondust lunar dust simulation and mitigation

The feasibility of extended exploration and human presence on the Moon and Mars depends critically on dealing with various environmental factors, and especially on the effects of dust. One of the most restricting facets of lunar surface exploration, as experienced by the prior Apollo landed missions, is the fine lunar dust, its high adherence, and its restrictive friction-like action. Moreover, the lunar dust particle size distribution extends generally into the submicron range, where it could potentially have toxic effects on exposed astronauts through their respiratory system. MoonDust is a project being performed in collaboration with the Canadian Space Agency to study the effects of lunar dust on optics and mechanical elements, and to develop innovative nano-filtration solutions to extend their operational lifetime within a lunar and/or Mars environment. To assist this work, a small lunar environment simulation vacuum chamber is being developed at MPBC, to enable the study of lunar dust effects on optics elements and rotary mechanisms, at pressures brought down below 10-5 Torr. The developed simulator includes an injection system for lunar dust simulants, an excimer UV laser-light source for vacuum UV (VUV), and various diagnostic ports for relevant optical and electrical measurements. The MoonDust innovative dust mitigation solution exploits key characteristics of the lunar dust while incorporating nano-filtration technologies based on carbon nanotubes (CNT) materials. The aim is to minimize the required consumables while providing high capacity and high efficiencies for the more dangerous submicron particles. This paper reports on the development of the lunar environmental chamber and the associated lunar dust simulator. Some of the preliminary trial experimental results for filters based on CNTs for optical devices and rotary mechanical joint protection are also presented

Moondust lunar dust simulation and mitigation

The feasibility of extended exploration and human presence on the Moon and Mars depends critically on dealing with various environmental factors, and especially on the effects of dust. One of the most restricting facets of lunar surface exploration, as experienced by the prior Apollo landed missions, is the fine lunar dust, its high adherence, and its restrictive friction-like action. Moreover, the lunar dust particle size distribution extends generally into the submicron range, where it could potentially have toxic effects on exposed astronauts through their respiratory system. MoonDust is a project being performed in collaboration with the Canadian Space Agency to study the effects of lunar dust on optics and mechanical elements, and to develop innovative nano-filtration solutions to extend their operational lifetime within a lunar and/or Mars environment. To assist this work, a small lunar environment simulation vacuum chamber is being developed at MPBC, to enable the study of lunar dust effects on optics elements and rotary mechanisms, at pressures brought down below 10-5 Torr. The developed simulator includes an injection system for lunar dust simulants, an excimer UV laser-light source for vacuum UV (VUV), and various diagnostic ports for relevant optical and electrical measurements. The MoonDust innovative dust mitigation solution exploits key characteristics of the lunar dust while incorporating nano-filtration technologies based on carbon nanotubes (CNT) materials. The aim is to minimize the required consumables while providing high capacity and high efficiencies for the more dangerous submicron particles. This paper reports on the development of the lunar environmental chamber and the associated lunar dust simulator. Some of the preliminary trial experimental results for filters based on CNTs for optical devices and rotary mechanical joint protection are also presented

Project Moondust: Characterization and mitigation of lunar dust

The feasibility of extended exploration and human presence on the Moon and Mars depends critically on dealing with the environmental factors, especially the intrusive effects of dust. The prior Apollo landed missions found that the lunar dust exhibited high adherence to exposed surfaces and a restrictive friction-like action causing premature wear of the EVA suits. MoonDust is a project being performed in collaboration with the Canadian Space Agency to study the effects of lunar dust on optics and mechanics, and to develop innovative solutions to extend their operational lifetime within a lunar or Mars environment based on the unique properties of carbon nanotube (CNT) nanocomposites. To assist this work, a small lunar environment simulation vacuum chamber has been set-up at MPB Communications to enable the study of lunar dust effects on optics and rotary mechanisms at pressures to below 10-5 Torr. New lunar dust simulants have been developed at the University of Winnipeg, characteristic of lunar Mare (UW-M1) and highland (UW-H1) compositions, which incorporate nanophase Fe in the silica particles. This paper describes the preliminary characterization of the various available lunar dust simulants that has included IR Raman and EDX for molecular an