| 1. |
- Andersson Ersman, Peter, et al.
(författare)
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All-printed large-scale integrated circuits based on organic electrochemical transistors
- 2019
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The communication outposts of the emerging Internet of Things are embodied by ordinary items, which desirably include all-printed flexible sensors, actuators, displays and akin organic electronic interface devices in combination with silicon-based digital signal processing and communication technologies. However, hybrid integration of smart electronic labels is partly hampered due to a lack of technology that (de)multiplex signals between silicon chips and printed electronic devices. Here, we report all-printed 4-to-7 decoders and seven-bit shift registers, including over 100 organic electrochemical transistors each, thus minimizing the number of terminals required to drive monolithically integrated all-printed electrochromic displays. These relatively advanced circuits are enabled by a reduction of the transistor footprint, an effort which includes several further developments of materials and screen printing processes. Our findings demonstrate that digital circuits based on organic electrochemical transistors (OECTs) provide a unique bridge between all-printed organic electronics (OEs) and low-cost silicon chip technology for Internet of Things applications. © 2019, The Author(s).
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| 2. |
- Andersson Ersman, Peter, et al.
(författare)
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Monolithic integration of display driver circuits and displays manufactured by screen printing
- 2020
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Ingår i: Flexible and Printed Electronics. - : Institute of Physics Publishing. - 2058-8585. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Here, we report all-screen printed display driver circuits, based on organic electrochemical transistors (OECTs), and their monolithic integration with organic electrochromic displays (OECDs). Both OECTs and OECDs operate at low voltages and have similar device architectures, and, notably, they rely on the very same electroactive material as well as on the same electrochemical switching mechanism. This then allows us to manufacture OECT-OECD circuits in a concurrent manufacturing process entirely based on screen printing methods. By taking advantage of the high current throughput capability of OECTs, we further demonstrate their ability to control the light emission in traditional light-emitting diodes (LEDs), where the actual LED addressing is achieved by an OECT-based decoder circuit. The possibility to monolithically integrate all-screen printed OECTs and OECDs on flexible plastic foils paves the way for distributed smart sensor labels and similar Internet of Things applications.
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| 3. |
- Berggren, Magnus, et al.
(författare)
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Browsing the Real World using Organic Electronics, Si-Chips, and a Human Touch
- 2016
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 28:10, s. 1911-1916
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Tidskriftsartikel (refereegranskat)abstract
- Two different e-labels were developed to explore the feasibility and to identify scientifi c and engineering challenges of the Real-World-Web platform. First was a printed biosensor e-label, comprising Si-chips with an array of different printegrated devices, and second, an e-label to explore the feasibility of transferring data, through the human body, between a mobile device and different distributed e-labels, adhered onto the body or onto dedicated devices and surfaces of one's ambience. The silicon chips utilized in e-labels, include analogue and digital circuitry to receive and handle sensory input, to perform signal processing, and to transmit information to antennas and displays. When used, the e-label is turned on, and a sample is then added onto the sensor area. The display provides simple instructions and updated information to the user. All data handling, electrical probing, and analysis of the sensor is performed by the Si-chips, and the sensing data is finally shown in the printed display. The second e-label exemplifies an ID-tag for body area networks (BAN) communication applications, which, in part, is manufactured and integrated in the same way as the first e-label, but with another choice of Si-chips and capacitive antennas.
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| 4. |
- Gustafsson, Jan-Erik, et al.
(författare)
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Loading and deformation of cigarette packages
- 2017
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Ingår i: 28th IAPRI Symposium on Packaging 2017. - 9782839921206 ; , s. 409-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Research has been undertaken to investigate the deformation properties of cigarette packages subjected to different loads. Numerical simulation enables a hypothetical package produced from a hypothetical paperboard to be tested. A finite element model was implemented in the Abaqus system in order to calculate stresses and strains in the deformed packages. The model behaves as expected up to deformations with limited damage. The calculated initial slopes of the reaction force responses were generally in good agreement with the corresponding measured slopes, although the model had a nonlinear force response that was not found in the experimental data. Incorporating cohesive behaviour into the model would allow the elements to disconnect from each other. Statistical analysis of the couplings between the initial process responses and the material properties of the paperboards revealed that only the initial yield stress parameter significantly affected the slope.
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| 5. |
- Gustafsson, Oscar, et al.
(författare)
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A performance assessment of type-II interband In0.5Ga 0.5Sb QD photodetectors
- 2013
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Ingår i: Infrared physics & technology. - : Elsevier BV. - 1350-4495 .- 1879-0275. ; 61, s. 319-324
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Tidskriftsartikel (refereegranskat)abstract
- Self-assembled quantum-dot (QD) structures with type-II band alignment to the surrounding matrix material have been proposed as a III/V material approach to realize small-bandgap device structures suitable for photon detection and imaging in the long-wavelength infrared (LWIR) band. Here, we analyze the photoresponse of In0.5Ga0.5Sb/InAs QD photodiodes and estimate the system performance of type-II QD -based photodetectors. A review of alternative design approaches is presented and the choice of matrix material is discussed in terms of band alignment and its effect on the photoresponse. Photodiodes were fabricated consisting of 10 layers of In0.5Ga 0.5Sb QDs grown on InAs (0 0 1) substrates with metal-organic vapor-phase epitaxy (MOVPE). The photoresponse and dark current were measured in single pixel devices as a function of temperature in the range 20-230 K. The quantum efficiency shows an Arrhenius type behavior, which is attributed to hole trapping. This severely limits the detector performance at typical LWIR sensor operating temperatures (60-120 K). A device design with the matrix material InAs0.6Sb0.4 is proposed as a mean to improve the performance by reducing the barrier for hole transport. This can potentially allow type-II InGaSb QDs to be a competitive sensor material for LWIR detection.
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| 6. |
- Gustafsson, Ola, et al.
(författare)
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Heat exchanger design aspects related to noise in heat pump applications
- 2016
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Ingår i: Applied Thermal Engineering. - : Elsevier. - 1359-4311 .- 1873-5606. ; 93, s. 742-749
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Tidskriftsartikel (refereegranskat)abstract
- An increased use of heat pumps is one of the measures that can be taken to reduce energy consumption on a large scale. For a wider acceptance, and major heat pump market expansion, it is crucial to develop heat pumps that cause minimal disturbance. Results from field measurements made by SP Technical Research Institute of Sweden indicate that the use of indirect heat pumps has potential to significantly reduce the outdoor noise level of ambient air heat pumps. The noise level caused by such heat pumps has been shown to be highly influenced by the design of the air-to-fluid heat exchanger. The overall purpose of this study is to propose a design of an air-to-fluid heat exchanger that allows for a well performing system as well as a low level of noise and cost. Two different types of heat exchangers, with flat tubes and round tubes, are compared theoretically. According to the modelling results, a heat exchanger with flat tubes and plain fins is the most suitable out of the studied designs due to its low heat transfer resistance on the tube side. The round tube heat exchangers showed to be significantly less suitable, displacing more than twice the volume.
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| 7. |
- Gustafsson, Oscar, et al.
(författare)
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Long-wavelength infrared photoluminescence from InGaSb/InAs quantum dots
- 2013
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Ingår i: Infrared physics & technology. - : Elsevier BV. - 1350-4495 .- 1879-0275. ; 59, s. 89-92
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Tidskriftsartikel (refereegranskat)abstract
- We study the growth of self-assembled InGaSb/InAs quantum dots (QDs) and investigate how gallium can be used to reduce the optical transition energy in the InSb QD system. InGaSb QDs were grown on InAs (0 0 1) substrates by metal-organic vapor-phase epitaxy (MOVPE) and the material was characterized by photoluminescence (PL) measurements. A PL peak wavelength is demonstrated beyond 8 μm at 77 K, which is significantly longer than what has been reported for InSb QDs. The results suggest that InGaSb QDs can be grown at a larger size than InSb QDs leading to reduced confinement in the QDs.
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| 8. |
- Gustafsson, Oscar, et al.
(författare)
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Photoluminescence photoresponse from InSb/InAs-based quantum dot structures
- 2012
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Ingår i: Optics Express. - : Optical Society of America. - 1094-4087. ; 20:19, s. 21264-71
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Tidskriftsartikel (refereegranskat)abstract
- InSb-based quantum dots grown by metal-organic vapor-phase epitaxy (MOVPE) on InAs substrates are studied for use as the active material in interband photon detectors. Long-wavelength infrared (LWIR) photoluminescence is demonstrated with peak emission at 8.5 μm and photoresponse, interpreted to originate from type-II interband transitions in a p-i-n photodiode, was measured up to 6 μm, both at 80 K. The possibilities and benefits of operation in the LWIR range (8-12 μm) are discussed and the results suggest that InSb-based quantum dot structures can be suitable candidates for photon detection in the LWIR regime.
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| 9. |
- Gustafsson, O., et al.
(författare)
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Reversing air-source heat pumps - Noise at defrost initiation and a noise reducing strategy
- 2016
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Ingår i: International Journal of Refrigeration. - : Elsevier BV. - 0140-7007 .- 1879-2081. ; 62, s. 137-144
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Tidskriftsartikel (refereegranskat)abstract
- With the increasing use of air source heat pumps, noise disturbance can be a barrier for further market growth and acceptance. Both steady state noise level and noise events influence reported noise disturbance. In this study one of the transient noise events was investigated: the noise initiated when the heat pump shifts to defrost mode. The results show that noise from a heat pump at defrost initiation was strongly dependent on the pressure differences in the system at the time of the shift. A reduced pressure difference resulted in a lower noise level. A control strategy that adds an idling time for the heat pump just before the shift of the 4-way valve is therefore suggested. This will have a small negative effect (<3%) on the heat capacity of the heat pump but the effect upon the COP will be negligible. (C) 2016 Elsevier Ltd and International Institute of Refrigeration. All rights reserved.
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| 10. |
- Holmgren, Jan, 1944, et al.
(författare)
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Development and preclinical evaluation of safety and immunogenicity of an oral ETEC vaccine containing inactivated E. coli bacteria overexpressing colonization factors CFA/I, CS3, CS5 and CS6 combined with a hybrid LT/CT B subunit antigen, administered alone and together with dmLT adjuvant
- 2013
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 31:20, s. 2457-2464
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Tidskriftsartikel (refereegranskat)abstract
- A first-generation oral inactivated whole-cell enterotoxigenic Escherichia coli (ETEC) vaccine, comprising formalin-killed ETEC bacteria expressing different colonization factor (CF) antigens combined with cholera toxin B subunit (CTB), when tested in phase III studies did not significantly reduce overall (generally mild) ETEC diarrhea in travelers or children although it reduced more severe ETEC diarrhea in travelers by almost 80%. We have now developed a novel more immunogenic ETEC vaccine based on recombinant non-toxigenic E. coli strains engineered to express increased amounts of CF antigens, including CS6 as well as an ETEC-based B subunit protein (LCTB. A), and the optional combination with a nontoxic double-mutant heat-labile toxin (LT) molecule (dmLT) as an adjuvant.Two test vaccines were prepared under GMP: (1) A prototype E. coli CFA/I-only formalin-killed whole-cell. +. LCTB. A vaccine, and (2) A "complete" inactivated multivalent ETEC-CF (CFA/I, CS3, CS5 and CS6 antigens) whole-cell. +. LCTB. A vaccine. These vaccines, when given intragastrically alone or together with dmLT in mice, were well tolerated and induced strong intestinal-mucosal IgA antibody responses as well as serum IgG and IgA responses to each of the vaccine CF antigens as well as to LT B subunit (LTB). Both mucosal and serum responses were further enhanced (adjuvanted) when the vaccines were co-administered with dmLT. We conclude that the new multivalent oral ETEC vaccine, both alone and especially in combination with the dmLT adjuvant, shows great promise for further testing in humans.
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