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Digital Cellulose : Recent Advances in Electroactive Paper
No full textWith the increasing global demand for net-zero carbon emissions, actions to address climate change have gained momentum among policymakers and the public. The urgent need for a sustainable economy is underscored by the mounting waste crisis in landfills and oceans. However, the proliferation of distributed electronic devices poses a significant challenge due to the resulting electronic waste. To combat this issue, the development of sustainable and environmentally friendly materials for these devices is imperative. Cellulose, an abundant and CO2-neutral substance with a long history of diverse applications, holds great potential. By integrating electrically interactive components with cellulosic materials, innovative biobased composites have been created, enabling the fabrication of bulk electroactive paper and the establishment of new, potentially more sustainable manufacturing processes for electronic devices. This review explores recent advances in bulk electroactive paper, including the fundamental interactions between its constituents, manufacturing techniques, and large-scale applications in the field of electronics. Furthermore, it addresses the importance and challenges of scaling up production of electroactive paper, highlighting the need for further research and development. The authors acknowledge financial support from Vinnova though the Digital Cellulose Center (DCC) (https://digitalcellulosecenter.se ) (diary number 2016-05193 and 2022-03085), the academic and industrial partners of DCC, the Knut and Alice Wallenberg Foundation via the Wallenberg Wood Science Center, and the Swedish Energy Agency (diary 2021-002347). The authors acknowledge support from Treesearch.se. The authors also thank Nicolas Tissier and Mahiar Hamedi for help with proofreading the manuscript.</p
Exploring Pathways to Circular Economy Practices in Estonian Manufacturing SMEs : A Fuzzy-Set QCA Approach on Stakeholder Pressure and Collaboration
No full textIn response to global imperatives for sustainability, particularly within the framework of the circular economy (CE), this study examines the adoption of CE practices among manufacturing Small and Medium Enterprises (SMEs) in Estonia. Based on a sample of 78 responses using complete case analysis, this research aims to uncover the configurations of stakeholder pressure (business and social) and collaboration (supply and demand-side) pathways that facilitate successful CE adoption. Drawing on Fuzzy-set Qualitative Comparative Analysis (fsQCA) and Configurational Theory, the study explores how interactions among these factors influence the adoption of CE practices. The empirical investigation, grounded in the Estonian context, reveals three key pathways driving CE adoption: demand-side collaboration, social pressure without direct business pressure, and the combination of business pressure with supply-side collaboration. The findings not only contribute theoretically by advancing configurational approaches in CE research but also offer practical implications for SME managers seeking to adopt CE practice. This work was supported by the Estonian Ministry of Education and Research through the Centre of Excellence in Circular Economy for Strategic Minerals and Carbon Resources (01.01.2024–31.12.2030, TK228).</p
Unipolar quantum optoelectronics for high speed direct modulation and transmission in 8–14 µm atmospheric window
No full textThe large mid-infrared (MIR) spectral region, ranging from 2.5 µm to 25 µm, has remained under-exploited in the electromagnetic spectrum, primarily due to the absence of viable transceiver technologies. Notably, the 8–14 µm long-wave infrared (LWIR) atmospheric transmission window is particularly suitable for free-space optical (FSO) communication, owing to its combination of low atmospheric propagation loss and relatively high resilience to turbulence and other atmospheric disturbances. Here, we demonstrate a direct modulation and direct detection LWIR FSO communication system at 9.1 µm wavelength based on unipolar quantum optoelectronic devices with a unprecedented net bitrate exceeding 55 Gbit s−1. A directly modulated distributed feedback quantum cascade laser (DFB-QCL) with high modulation efficiency and improved RF-design was used as a transmitter while two high speed detectors utilizing meta-materials to enhance their responsivity are employed as receivers; a quantum cascade detector (QCD) and a quantum-well infrared photodetector (QWIP). We investigate system tradeoffs and constraints, and indicate pathways forward for this technology beyond 100 Gbit s−1 communication. This work was supported in part by the EU H2020 cFLOW Project (828893), in part by the Swedish Research Council (VR) project 2019-05197 and project ‘BRAIN’ 2022-04798, in part by the COST Action CA19111 NEWFOCUS, VINNOVA-funded project ‘A-FRONTHAUL’ 2023-00659, and in part by the LZP FLPP project ‘MIR-FAST’ (lzp-2023/1-0503). The authors from ENS acknowledge the financial support of the ENS-Thales Chair, Direction Générale de l’Armement (DGA), PEPRElectronique, ANR project LIGNEDEMIR (ANR- 18CE09-0035), FETOpen projects cFLOW (Grant No. 828893) and CNRS Renatechnetwork.</p
Integrated Energy Systems Modeling with Multi-Criteria Decision Analysis and Stakeholder Engagement for Identifying a Sustainable Energy Transition
No full textThe aim of this paper is to present a decision support system (DSS) to capture the complexity of the transition of a national energy system to net zero in the context of multiple sustainability themes. The paper proposes an integrated assessment framework that combines dynamic systems modeling, sustainability indicators, and multi-criteria decision analysis (MCDA) with direct stakeholder involvement. To illustrate the use of the DSS, the paper compares bundles of climate change policies that aim to decarbonize the road transport sector in Iceland. Eighteen scenarios and alternative development trajectories are defined for the Icelandic energy system based on a combination of three main driving forces. These are, firstly, economic development (three cases); secondly, changes in energy efficiency (two cases); and finally, three climate policy bundles aimed at increasing the share of electric vehicles. Based on the results from the integrated assessment framework, the performance scores of the climate policy bundles are compared across the following five sustainability themes: social impact; economic development; environmental impact; energy security; and technical aspects. The findings confirm that a different conclusion may be reached when multiple sustainability themes are applied in the selection of preferred policy bundles as compared to conventional techno-economic criteria. Banning the registration of fossil-fueled vehicles, combined with economic instruments, offers the best decarbonizing strategy to reach climate and energy policy goals simultaneously. This research was funded by the Icelandic Centre for Research, grant number: 163464-051.</p
Ionic liquids enhance electrical conductivity of greases : an impedance spectroscopy study
No full textIonic liquids (ILs) have emerged as viable solutions for developing new-age lubricants, both as neat lubricants and lubricant additives. Enabled by the presence of discrete ions, ILs have the possibility to render electrically conductive lubricants, which is a feasible strategy for developing lubricant systems compatible with modern e-drive conditions. However, this requires the characterization of the electrical properties of lubricants, which is a bottleneck for developing electrically conductive greases, given their complex architecture. This work introduces an electrochemical impedance spectroscopy measurement methodology to evaluate grease samples’ electrical properties. Compared to the commonly used conductivity meters, this method, through its multi-frequency alternating current (AC) impedance approach, can effectively distinguish the individual contributions of the bulk and the sample-electrode interface to the measured electrical response. Impedance spectra of grease samples are obtained using an electrochemical cell with parallel plate electrodes, mounted on a temperature-controlled cell stand and coupled with a potentiostat. The grease’s bulk conductivity is extracted by fitting the impedance data to relevant equivalent electrical circuits. The bulk conductivity of lithium complex grease doped with ILs is evaluated and compared to greases with conventional conductivity additives (copper powder and conductive carbon black). The analysis of temperature-dependent conductivity reveals the rather different conductivity mechanisms for different additives. For greases doped with ILs, a comparison against the electrical conductivity of neat ILs reveals that, in addition to the ion dissociation, the interaction of the ions with the different grease components (base oil, thickener) is crucial in defining the grease conductivity. The Swedish Foundation for Strategic Research (project EM16-0013 ), the Swedish Research Council (project 2018-05017 ), the Swedish Energy Agency, Sweden (project 2019-002238 ), and the Knut and Alice Wallenberg Foundation, Sweden (project KAW2012.0078 ) are gratefully acknowledged for financial support. The authors also would like to thank Dr. Marcel Druschler and Dr. Jens Wallauer from RHD instruments GmbH & Co. KG, Germany, for their invaluable insight into EIS measurements.</p
Electrically tunable infrared optics enabled by flexible ion-permeable conducting polymer-cellulose paper
No full textMaterials that provide dynamically tunable infrared (IR) response are important for many applications, including active camouflage and thermal management. However, current IR-tunable systems often exhibit limitations in mechanical properties or practicality of their tuning modalities, or require complex and costly fabrication methods. An additional challenge relates to providing compatibility between different spectral channels, such as allowing an object to be reversibly concealed in the IR without making it appear in the visible range. Here, we demonstrate that conducting polymer-cellulose papers, fabricated through a simple and cheap approach, can overcome such challenges. The papers exhibit IR properties that can be electrochemically tuned with large modulation (absolute emissivity modulation of 0.4) while maintaining largely constant response in the visible range. Owing to high ionic and electrical conductivity, the tuning of the top surface can be performed electrochemically from the other side of the paper even at tens of micrometer thicknesses, removing the need for overlaying electrode and electrolyte in the optical beam path. These features enabled a series of electrically tunable IR devices, where we focus on demonstrating dynamic radiative coolers, thermal camouflage, anti-counterfeiting tags, and grayscale IR displays. The conducting polymer-cellulose papers are sustainable, cheap, flexible and mechanically robust, providing a versatile materials platform for active and adaptive IR optoelectronic devices. (Figure presented.). The authors gratefully acknowledge support from the Swedish ResearchCouncil (VR, 2020-00287, 2022-00211, 2022-06214, and 2019-04424), andthe Knut and Alice Wallenberg Foundation, Linköping University andindustry through the Wallenberg Wood Science Center. We alsoacknowledge the European Research Council (Consolidator grant,101086683), the Swedish Foundation for International Cooperation inResearch and Higher Education (STINT), and the Swedish GovernmentStrategic Research Area in Materials Science on Functional Materials atLinköping University (Faculty Grant SFO-Mat-LiU No. 2009 00971). A.R.acknowledges support from the Marie Sklodowska-Curie Actions Seal ofExcellent Fellowship program from the Sweden’s Innovation Agency (Vinnova grant 2021-01668). J.E. acknowledges support from the Digital Cellulose Center (Vinnova). M.P.J. and K.T. are Wallenberg Academy Fellows.</p
Effect of ethylene oxide and gamma sterilization on surface texture of films and electrospun poly(ε-caprolactone-co-p-dioxanone) (PCLDX) scaffolds
No full textIn the field of tissue engineering, synthetic and degradable polyesters like poly(ε-caprolactone) (PCL) and poly(ε-caprolactone-co-p-dioxanone) (PCLDX) are widely used as scaffolds. Our previous research revealed that thermal storage conditions could alter the surface texture of PCL and PCLDX scaffolds, which might influence cell-scaffold interactions in tissue engineering applications. These findings highlighted the importance of multi-scale characterization techniques to identify the scales most sensitive to external changes and the need for personalized surface texture analysis. Sterilization techniques, such as ethylene oxide and gamma radiation, are essential for ensuring the sterility of polymeric medical devices. However, these processes can significantly impact the bulk polymer properties and/or surface texture of the scaffolds, potentially affecting their biocompatibility, safety, and overall performance. Therefore, the influence of sterilization processes on the surface texture of PCLDX films and electrospun nanofibers and to correlate these findings with the thermal and physical properties of the polymer are essential and have been assessed. Our results demonstrated that ethylene oxide maintained the structural integrity and surface texture of PCLDX scaffolds, while gamma irradiation caused a significant reduction in molar mass and increased the number of hills (Shn) and dales (Sdn) on PCLDX samples. Despite these changes, both sterilization methods showed minimal effects on the thermal properties, such as melting temperature and degree of crystallinity, and surface wettability of the scaffolds. This comprehensive surface texture analysis highlights the importance of evaluating feature parameters such as Shn and Sdn for optimizing the performance and biocompatibility of polymeric scaffolds in tissue engineering. This work is conducted within the Additive Manufacturing for the Life Sciences Competence Center (AM4Life). The authors gratefully acknowledge financial support from Sweden’s Innovation Agency VINNOVA (Grant no: 2019-00029).</p
Adapting International Business Models for EU Projects: Macro- and Micro-Foundations of the Uppsala Model in Multinational Collaborations
No full textThis study examines the adaptation of the Uppsala Model to enhance the management of European Union (EU)-funded projects, particularly focusing on the macro- and micro-foundational elements of the model. The Uppsala Model, originally developed for firm-level internationalization, provides a valuable framework for addressing the complex challenges of EU project implementation, which include bureaucratic hurdles, diverse stakeholder management, and the intricacies of European integration. This paper highlights the persistent issues faced by project managers despite improved application processes and skilled beneficiaries. By applying the Uppsala Model, which emphasizes incremental knowledge development and resource commitment, this study aims to bridge the gap between fund acquisition and project delivery. The integration of both macro- (broad external factors) and micro- (individual and organizational behaviors) perspectives of the Uppsala Model offers a comprehensive approach to managing international, multi-stakeholder EU initiatives. This approach is exemplified through the SuMaNu project, which addresses nutrient recycling and sustainable manure management in the Baltic Sea Region. The findings suggest that the Uppsala Model’s principles can be effectively applied to enhance the execution of complex EU projects by fostering better stakeholder relationships, incremental learning, and adaptive strategies. This study underscores the relevance of experiential learning and network perspectives in achieving successful project outcomes in the EU contex
Situating the discourse of recycled nutrient fertilizers in circular economy principles for sustainable agriculture
No full textThis mini-review is part of the EU Interreg Baltic Sea Region (BSR) funded core project #C049 titled CiNURGi, under the PROGRAMME 2021-2027, priority 3 Climate-neutral societies, objective 3.1 Circular economy.</p
Säker storskalig vätgasbunkring - Test och validering
No full textSafe large scale hydrogen bunkering - Test and validation The project investigates the use of green hydrogen as a sustainable fuel for shipping. It focuses on developing and validating a new cylinder design with built-in cooling to handle temperature increases during bunkering. The project aims to validate and analyze this new cylinder design by manufacturing a prototype equipped with heat exchangers and conducting performance tests. The project has been carried out in three stages: prototype development, pressure and safety tests, and performance tests. The prototype tank passed both pressure and performance tests without leaking or visible damage. The cylinder design with built-in heat exchanger was found to be able to limit the temperature rise during hydrogen bunkering, enabling a higher fill rate and safe use. However, there are still open questions regarding a large-scale filling that should be investigated further in future projects to further optimize the process. Among other things, this applies to the influence of a plastic liner or a thinner metal liner, a larger tank volume, larger mass flows and realistic pipe/hose lengths and dimensions between the expansion valve and the tanks on board.Detta är en slutrapport för ett forskningsprojekt finansierat genom Trafikverkets program för forskning och innovation inom sjöfartsområdet, ärendenummer TRV 2023/33491. Projektet har genomförts av RISE Research Institute of Sweden, RISE Fire Research AS, Kungliga Tekniska Högskolan (KTH) och Uppsala Universitet (UU).</p