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Research and development of small satellites has continued to expand over the last decades. However, propulsion systems with adequate performance have persisted to be a great challenge. In this paper, the effects of three different heaters on the specific impulse and overall thrust efficiency of a cold gas microthruster are presented. They consisted of a conventional, printed resistive thick-film element, a freely suspended wire, and a stripline split-ring resonator microplasma source and were integrated in a single device made from high-temperature co-fired ceramics (HTCC). The devices were evaluated in two setups, where the first measured thrust and the other shock cell geometry. In addition, the resistive elements were evaluated as gas temperature sensors. The microplasma source was found to provide the greatest improvement in both specific impulse and thrust efficiency, increasing the former from an un- heated level of 44 s to 55 s when heating with a power of 1.1 W. This corresponded to a thrust efficiency of 53 %. This could be compared to the results from the wire and printed heaters which were 50 s and 18 %, and 45 s and 14 %, respectively. The combined results also showed that imaging the shock cells of a plasma heated thruster was a simple and effective way to determine its performance compared to the traditional thrust balance method.

This paper presents the integration and pressure sensor operation of platinum bond wires in High- Temperature Co-fired alumina (HTCC). Devices were fabricated with a 50 μm diameter wire suspended across a 500 μm wide cavity in green-body state HTCC, electrically connected to screen printed alumina conductors. The substrate shrinkage during sintering to a cavity width of 400 μm causes the wire element to elevate from the cavity ́s bottom surface. Resulting devices were compared with reference devices, containing screen-printed sensor elements, as Pirani gauges operated at 100 °C in constant-resistance mode, and in dynamic mode with a feeding current of 1 A in a pressure range from 10-4 Torr to atmospheric pressure. Also, devices with wire lengths between 500 and 3500 μm were operated and studied in constant-resistance and dynamic mode. Lastly, a device is demonstrated in operation at a mean temperature of 830 °C. The results include wire elements with a consistent elevation from their substrate surfaces, with irregularities along the wires. The wire devices exhibit a faster pressure response in dynamic mode than the reference devices do but operate similarly in constant-resistance mode. Increasing the wire element length shows an increasing dynamic pressure range but a decreasing maximum sensitivity. The sensitivity is retained in high temperature mode, but the dynamic range is extended from about 10 Torr to about 700 Torr.

In aerospace applications, but also in manufacturing, mining, energy industry and natural hazards, high temperature, corrosion, erosion and radiation, challenge the performance and being of hardware.

In this work, high-temperature co-fired ceramic (HTCC) alumina and platinum have been used for a range of devices intended for aerospace applications at up to 1000°C.

The thermomechanics of a pressure sensor was investigated, and the interfacing was attained by wireless powering and reading. However, read range was limited and sensitivity decreased with temperature. Silver, electroplated after sintering, was found to remedy this until it eventually alloyed with platinum.

Copper was electroplated and oxidized for oxygen storage in a microcombustor, intended for sample preparation for optogalvanic spectroscopy (OGS) to indicate extraterrestrial life. Despite delamination, caused by residual stresses, the device operated successfully.

Conversely, pre-firing metallization by integration of platinum wires was studied. Freely suspended, and despite heat-induced shape irregularities, these were found advantageous over screen printed elements for gas heating, and temperature and pressure sensing. By fusing off the wires, spherical tips, allowing for impedance monitoring of microplasma sources in, e.g., OGS, were formed.

Microplasma sources can also be used for gas heating. This, together with screen printed and suspended resistive heaters, was evaluated in a microthruster, showing that plasma heating is the most effective, implying fuel consumption reduction in satellite propulsion.

In conclusion, HTCC alumina microdevices are thermally stable and could benefit several aerospace applications, especially with the complementary metallization schemes devised here.

Future developments are expected to include both processing and design, all with the intention of sensing, actuating and surviving in high-temperature environments.

Summary

Four technology forecast reports from the Fraunhofer Institute and two reports from the Swedish Defence Research Agency (FOI) have been reviewed by staff at the Military Technology Division at the Swedish Defence University (SEDU). The task given by the Defence Materiel Administration (FMV) was to assess the military utility of the given technologies in a timeframe up to the year 2040, from a Swedish Armed Forces (SwAF) perspective.

In the review, we assess the military utility of certain technologies as possible contributions to the operational capabilities of the SwAF, based on identified and relevant scenarios.

The technologies are grouped into four classes of military utility: potentially significant, moderate, negligible or uncertain.

The following technologies were assessed to have the potential for significant military utility:

• Rapid field      identification of harmful microorganisms
• Hypersonic      propulsion

The following technologies were assessed to have a potential for moderate military utility:

• Non-line-of-sight      imaging
• Artificial      intelligence for military decision support

The following technologies were assessed to have uncertain military utility:

• Structural      energy storage
• Triboelectric      nanogenerators

No technology was found to have negligible military utility.

The method used in this technology forecast report was to assign each report to one reviewer in the working group. Firstly, each forecast report was summarized. A new methodological step this year was for each reviewer to discuss the assigned technologies with researchers from FOI. This proved to be a valuable enhancement for understanding the technologies’ present state and likely future development.

The chosen definition of military utility clearly affects the result of the study. The definition used here, ‘the military utility of a certain technology is its contribution to the operational capabilities of the SwAF, within identified relevant scenarios’ has been used in our Technology Forecasts since 2013.

Our evaluation of the method used shows that there is a risk that assessments can be biased by the participating experts’ presumptions and experience from their own field of research. It should also be stressed that the six technologies’ potential military utility was assessed within the specific presented scenarios and their possible contribution to operational capabilities within those specific scenarios, not in general. When additional results have been found in the analysis, this is mentioned.

The greatest value of the method used is its simplicity, cost effectiveness and that it promotes learning within the working group. The composition of the working group and the methodology used are believed to provide a broad and balanced coverage of the technologies being studied. This report should be seen as an executive summary of the research reports and the intention is to help the SwAF Headquarters to evaluate the military utility of emerging technologies within identified relevant scenarios.

Overall, the research reports are considered to be balanced and of high quality in terms of their level of critical analysis regarding technology development. These reports are in line with our task to evaluate the military utility of the emerging technologies.

A first realization of membranes by draping a graphite insert with ceramic green body sheets, and a study on the relationship between circuit metallization, made by double- layer screen-printing of platinum and electroplating of silver on top of platinum, and the practical read range of ceramic LC resonators for high-temperature pressure measurements, are presented. As a quality factor reference, two-port microstrip meander devices were positively evaluated. To study interdiffusion between silver and platinum, test samples were annealed at 500, 700, and 900 °C for 4, 36, 72, and 96 hours. The LC resonators were fabricated with both metallization methods, and the practical read range at room temperature was evaluated. Pressure sensitive membranes were characterized for pressures up to 2.5 bar at room temperature, 500 and up to 900°C. Samples electroplated with silver exhibited performance equal to or better than double-layer platinum samples for up to 60 hours at 500°C, 20 hours at 700°C, and for 1 hour at 900°C, which was correlated with the degree of interdiffusion as determined from cross- sectional analysis. The LC resonator samples with double-layer platinum exhibited a read range of 61 mm, and the samples with platinum and silver exhibited a read range of 59 mm. The lowest sheet resistance, and, thereby, the highest read range of 86 mm, was obtained with a silver electroplated LC resonator sample after 36 hours of annealing at 500°C. 

Two technology forecast reports from the Fraunhofer Institute, three reports from the Swedish Defence Research Institute (FOI) and two publications from the Massachusetts Institute of Technology (MIT) have been reviewed by staff at the Military-Technology Division at the Swedish Defence University (SEDU). The task given by the Defence Material Administration (FMV) was to assess the military utility of the given technologies in a time frame to up 2040, from a Swedish Armed Forces (SwAF) perspective.

In the review we assessed the military utility of certain technologies as possible contributions to the operational capabilities of the SwAF, based on identified and relevant scenarios. Because a new capability catalogue is under development at the SwAF Headquarters, this report only presents general assessments of the capability impact of the technologies studied.

The technologies were grouped into four classes: potentially significant, moderate, negligible, or uncertain military utility.

The classification uncertain military utility was given to technologies that are difficult to put in the other three classes, it was not because the technology readiness level (TRL) will not bereached by 2040.

The following technologies were assessed to have the potential for significant military utility:

- Nanocarbons for photonic applications

The following technologies were assessed to have a potential for moderate military utility;

- Internet of things (IoT)

- Materials and technologies for protection against chemical agents

The following technologies were assessed to have uncertain military utility;

- Post-quantum cryptography

- New applications for hyperspectral image analysis for chemical and biological agents

No technology was found to have negligible military utility.

The method used in this technology forecast report was to assign each report to one reviewer in the working group. Firstly, each forecast report was summarized. The Fraunhofer assessment of technical readiness level (TRL) in the time period was held to be correct. Each technology was then put into one or more scenarios that were assessed to be suitable for assessing the military utility as well as indicating any possibilities and drawbacks. Based on a SWOTanalysis, the assessed contributions to the fundamental capabilities, and to the factors DOTMPLFI (Doctrine, Organization, Training, Materiel, Leadership, Personnel, Facilities and Interoperability), were listed. Furthermore, the expected SwAF R&D requirements, to facilitate the introduction of the technology are given. The Military utility was assessed using a model developed by the Military-Technology Division. Finally, conclusions and an overall rating of the potential military utility of each technology were presented.

The chosen definition of military utility clearly affects the result of the study. The definition used here (“the military utility of a certain technology is its contribution to the operational capabilities of the SwAF, within identified relevant scenarios”) has been used in our Technology Forecasts since 2013.

Our evaluation of the method used shows that there is a risk that assessments can be biased by the participating experts’ presumptions and experience from their own field of research. It should also be stressed that the seven technologies’ potential military utility was assessed within the specific presented scenarios and their possible contribution to operational capabilities within those specific scenarios, not in general. When additional results have been found in the analysis, this is mentioned.

The greatest value of the method used is its simplicity, cost effectiveness and that it promotes learning within the working group. The composition of the working group and the methodology used are believed to provide a broad and balanced coverage of the technologies being studied. This report should be seen as an executive summary of the research reports and the intention is to help the SwAF Headquarters to evaluate the military utility of emerging technologies within identified relevant scenarios.

Overall, the research reports are considered to be balanced and of high quality in terms of their level of critical analysis regarding technology development. These reports are in line with our task to evaluate the military utility of the emerging technologies.

Miniaturized optogalvanic spectroscopy (OGS) shows excellent prospects for becoming a highly sensitive method for gas analysis in micro total analysis systems. Here, a status report on the current development of microwave-induced microplasma sources for OGS is presented, together with the first comparison of the sensitivity of the method to conventional single-pass absorption spectroscopy. The studied microplasma sources are stripline split-ring resonators, with typical ring radii between 3.5 and 6mm and operation frequencies around 2.6 GHz. A linear response (R2 = 0.9999), and a stability of more than 100 s are demonstrated when using the microplasma source as an optogalvanic detector. Additionally, saturation effects at laser powers higher than 100 mW are observed, and the temporal response of the plasma to periodic laser perturbation with repletion rates between 20 Hz and 200 Hz are studied. Finally, the potential of integrating additional functionality with the detector is discussed, with the particular focus on a pressure sensor and a miniaturized combustor to allow for studies of solid samples.

Three technology forecast reports from the Fraunhofer Institute and four reports on literature studies (sometimes called scanning reports) from the Swedish Defence Research Institute (FOI) have been reviewed by staff at the Military-Technology Division at the Swedish Defence University (SEDU). The task given by the Defence Material Administration FMV was to assess the military utility of the given technologies in a time frame to 2040, from a Swedish Armed Forces (SwAF) point of view.

In the review we assess the military utility of a certain technology as a possible contribution to the operational capabilities of the SwAF, based on identified relevant scenarios. Since a new capability catalogue is under development at the SwAF Headquarters, this report will only present general assessments of the capability impact from the technologies under study.

The technologies were grouped into four classes: potentially significant, moderate, negligible, or uncertain military utility.

The following technology was assessed to have a potential for significant military utility;

 Multi robot systems

The following technologies were assessed to have a potential for moderate military utility;

 Over-the-Horizon Radar

 Space-based imaging radar

The following technology was found to have negligible military utility.

 Moving Target Defence

The following technologies were assessed to have uncertain military utility;

 Software-Defined Networking

 Transient Materials- Programmed to Perish, but this technology should be monitored since it might reach high technical readiness level (TRL) by 2050-60

The method used in this technology forecast report was to assign each report to one reviewer in the working group. First, a summary of each forecast report was made. The Fraunhofer assessment of TRL in the time period to 2035 was held to be correct. The technology was then put into one or more scenarios that were deemed to be suitable in order to assess the military utility as well as indicate possibilities and drawbacks of each technology. Based on a SWOT-analysis, the assessed contribution to the fundamental capabilities and to the factors DOTMPLFI (Doctrine, Organization, Training, Materiel, Personnel, Leadership, Facilities and Interoperability) were listed. Furthermore, the expected requirements on the SwAF R&D in order to facilitate the introduction of the technology are given.

As a consequence of our continuing development of the evaluation process, we have for the first time used a model developed at the division of Military-Technology to assess the Military utility1 of the technologies. Finally, conclusions and an overall rating regarding the potential military utility of each technology were presented.

The chosen definition of military utility clearly affects the result of the study. The definition (the military utility of a certain technology is its contribution to the operational capabilities of the SwAF, within identified relevant scenarios) is the same as used in our Technology Forecasts since 2013.

Our evaluation of the method used shows that there is a risk that the assessment is biased by the participating experts’ presumptions and experiences from their own field of research. Also, it should be stressed that the six technologies’ potential military utility was assessed within the specific presented scenarios, and their possible contribution to operational capabilities within those scenarios, not in general. When additional results have been found in the analysis this is mentioned. The last chapter of this report analyzes thinking and debate on war and warfare in three military great powers: USA, Russia and China. Therefore, this chapter has a different structure. Aspects of military technology are discussed at the end of the chapter, but no assessment of the military utility is made.

The greatest value of the method used is its simplicity, cost effectiveness and that it promotes learning within the working group. The composition of the working group and the methodology used is believed to provide a broad and balanced coverage of the technologies under study. This report is to been seen as an executive summary of the Fraunhofer reports and the reports on literature studies from FOI. The intention is to help the SwAF Headquarters to evaluate the military utility of emerging technologies within identified relevant scenarios.

Overall, the quality of the Fraunhofer reports is considered to be balanced and of a high level of critical analysis regarding technology development. These reports are in line with our task to evaluate the military utility of the emerging technologies. The FOI reports are considered to be high quality. However, the selection of topics can be discussed since the selection

A microscale ceramic high-temperature combustor with a built-in temperature sensor and source of oxygen has been designed, manufactured and characterized. The successful in situ electroplating and oxidation of copper, and the use of copper oxide as the source of oxygen were demonstrated. It was shown that residual stresses from electroplating, copper oxidation and oxide decomposition did not cause much deformation of the substrate but influenced mainly the integrity and adhesion of the metal films. The process had influence on the electrical resistances, however. Calibration of the temperature sensor and correlation with IR thermography up to 1000 °C revealed a nearly linear sensor behavior. Demonstration of combustion in a vacuum chamber proved that no combustion had occurred before release of oxygen from the metal oxide resource.

This paper reports on a novel method for manufacturing microscopic Langmuir probes with spherical tips from platinum bond wires by fusing for plasma characterization in microplasma sources. Here, the resulting endpoints, formed by droplets on the ends of a fused wire, are intended to act as spherical Langmuir probes. For studying the fusing behavior, bond wires were wedge bonded over a 2 mm wide slit, to emulate the final application, and fused with different voltages and currents. For electrical isolation, a set of wires were coated with a 4 μm thick layer of Parylene before they were fused. After fusing, the gap size, as well as the shape and area of the ends of the remaining stubs were measured. The yield of the process was also investigated, and the fusing event was studied using a high-speed camera for analyzing its dynamics. Four characteristic tip shapes were observed: spherical, folded, serpentine shaped and semi-spherical. The stub length leveled out at  ~400 μm as the fusing power increased. The fusing of the coated wires required a higher power to yield a spherical shape. Finally, a Parylene coated bond wire was integrated into a stripline split-ring resonator (SSRR) microplasma source, and was fused to form two Langmuir probes with spherical endpoints. These probes were used for measuring the I–V characteristics of a plasma generated by the SSRR. In a voltage range between  −60 V and 60 V, the fused stubs exhibited the expected behavior of spherical Langmuir probes, and will be considered for further integration.