miun.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Publications (10 of 21) Show all publications
Molina-Lopez, F., Gao, T. Z., Kraft, U., Zhu, C., Öhlund, T., Pfattner, R., . . . Bao, Z. (2019). Inkjet-printed stretchable and low voltage synaptic transistor array. Nature Communications, 10(1), Article ID 2676.
Open this publication in new window or tab >>Inkjet-printed stretchable and low voltage synaptic transistor array
Show others...
2019 (English)In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, no 1, article id 2676Article in journal (Refereed) Published
Abstract [en]

Wearable and skin electronics benefit from mechanically soft and stretchable materials to conform to curved and dynamic surfaces, thereby enabling seamless integration with the human body. However, such materials are challenging to process using traditional microelectronics techniques. Here, stretchable transistor arrays are patterned exclusively from solution by inkjet printing of polymers and carbon nanotubes. The additive, non-contact and maskless nature of inkjet printing provides a simple, inexpensive and scalable route for stacking and patterning these chemically-sensitive materials over large areas. The transistors, which are stable at ambient conditions, display mobilities as high as 30 cm2 V−1 s−1 and currents per channel width of 0.2 mA cm−1 at operation voltages as low as 1 V, owing to the ionic character of their printed gate dielectric. Furthermore, these transistors with double-layer capacitive dielectric can mimic the synaptic behavior of neurons, making them interesting for conformal brain-machine interfaces and other wearable bioelectronics. 

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-36690 (URN)10.1038/s41467-019-10569-3 (DOI)000471871700001 ()2-s2.0-85067603295 (Scopus ID)
Available from: 2019-07-09 Created: 2019-07-09 Last updated: 2019-10-16Bibliographically approved
Zhang, R., Hummelgård, M., Forsberg, V., Andersson, H., Engholm, M., Öhlund, T., . . . Olin, H. (2018). Photoconductivity of acid exfoliated and flash-light-processed MoS2 films. Scientific Reports, 8, Article ID 3296.
Open this publication in new window or tab >>Photoconductivity of acid exfoliated and flash-light-processed MoS2 films
Show others...
2018 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 3296Article in journal (Refereed) Published
Abstract [en]

MoS2 has been studied intensively during recent years as a semiconducting material in several fields, including optoelectronics, for applications such as solar cells and phototransistors. The photoresponse mechanisms of MoS2 have been discussed but are not fully understood, especially the phenomenon in which the photocurrent slowly increases. Here, we report on a study of the photoresponse flash-light-processed MoS2 films of different thicknesses and areas. The photoresponse of such films under different light intensities and bias voltages was measured, showing significant current changes with a quick response followed by a slow one upon exposure to pulsed light. Our in-depth study suggested that the slow response was due to the photothermal effect that heats the MoS2; this hypothesis was supported by the resistivity change at different temperatures. The results obtained from MoS2 films with various thicknesses indicated that the minority-carrier diffusion length was 1.36 mu m. This study explained the mechanism of the slow response of the MoS2 film and determined the effective thickness of MoS2 for a photoresponse to occur. The method used here for fabricating MoS2 films could be used for fabricating optoelectronic devices due to its simplicity.

National Category
Physical Sciences
Identifiers
urn:nbn:se:miun:diva-33302 (URN)10.1038/s41598-018-21688-0 (DOI)000425380900079 ()29459668 (PubMedID)2-s2.0-85061713034 (Scopus ID)
Available from: 2018-03-19 Created: 2018-03-19 Last updated: 2019-09-23Bibliographically approved
Samyn, P., Barhoum, A., Öhlund, T. & Dufresne, A. (2018). Review: Nanoparticles and Nanostructured Materials in Papermaking. Journal of Materials Science, 53(1), 146-184
Open this publication in new window or tab >>Review: Nanoparticles and Nanostructured Materials in Papermaking
2018 (English)In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 53, no 1, p. 146-184Article in journal (Refereed) Published
Abstract [en]

The introduction of nanoparticles (NPs) and nanostructured materials (NSMs) in papermaking originally emerged from the perspective of improving processing operations and reducing material consumption. However, a very broad range of nanomaterials (NMs) can be incorporated into the paper structure and allows creating paper products with novel properties. This review is of interdisciplinary nature, addressing the emerging area of nanotechnology in papermaking focusing on resources, chemical synthesis and processing, colloidal properties, and deposition methods. An overview of different NMs used in papermaking together with their intrinsic properties and a link to possible applications is presented from a chemical point of view. After a brief introduction on NMs classification and papermaking, their role as additives or pigments in the paper structure is described. The different compositions and morphologies of NMs and NSMs are included, based on wood components, inorganic, organic, carbon-based, and composite NPs. In a first approach, nanopaper substrates are made from fibrillary NPs, including cellulose-based or carbon-based NMs. In a second approach, the NPs can be added to a regular wood pulp as nanofillers or used in coating compositions as nanopigments. The most important processing steps for NMs in papermaking are illustrated including the internal filling of fiber lumen, LbL deposition or fiber wall modification, with important advances in the field on the in situ deposition of NPs on the paper fibers. Usually, the manufacture of products with advanced functionality is associated with complex processes and hazardous materials. A key to success is in understanding how the NMs, cellulose matrix, functional additives, and processes all interact to provide the intended paper functionality while reducing materials waste and keeping the processes simple and energy efficient.

National Category
Materials Chemistry
Identifiers
urn:nbn:se:miun:diva-31490 (URN)10.1007/s10853-017-1525-4 (DOI)000412900500007 ()2-s2.0-85029183594 (Scopus ID)
Available from: 2017-09-15 Created: 2017-09-15 Last updated: 2018-02-22Bibliographically approved
Balliu, E., Andersson, H., Engholm, M., Öhlund, T., Nilsson, H.-E. & Olin, H. (2018). Selective laser sintering of inkjet-printed silver nanoparticle inks on paper substrates to achieve highly conductive patterns. Scientific Reports, 8(1), Article ID 10408.
Open this publication in new window or tab >>Selective laser sintering of inkjet-printed silver nanoparticle inks on paper substrates to achieve highly conductive patterns
Show others...
2018 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, no 1, article id 10408Article in journal (Refereed) Published
Abstract [en]

Development of cost-effective and environmentally friendly manufacturing methods will enable important advances for the production of large-scale flexible electronics. Laser processing has shown to be a promising candidate that offers a fast and non-destructive way to produce highly conductive patterns on flexible substrates such as plastics. However, an emerging option with a lower environmental impact is instead the use of cellulose-based flexible substrates, such as paper. In this work we investigate the use of laser sintering of silver nanoparticle inks, which were inkjet-printed on three different types of paper. Patterns with a high conductivity could be manufactured where a special care was taken to prevent the substrates from damage by the intense laser light. We found that the best results was obtained for a photopaper, with a conductivity of 1.63 107 S/m corresponding to nearly 26% of the bulk silver conductivity. In addition, we demonstrate laser sintering to fabricate a fully functional near field communication tag printed on a photopaper. Our results can have an important bearing for the development of cost-effective and environmentally friendly production methods for flexible electronics on a large scale. 

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-34558 (URN)10.1038/s41598-018-28684-4 (DOI)000438024500040 ()2-s2.0-85049841147 (Scopus ID)
Available from: 2018-09-28 Created: 2018-09-28 Last updated: 2019-03-15Bibliographically approved
Barhoum, A., Samyn, P., Öhlund, T. & Dufresne, A. (2017). Review of recent research on flexible multifunctional nanopapers. Nanoscale, 9(40), 15181-15205
Open this publication in new window or tab >>Review of recent research on flexible multifunctional nanopapers
2017 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 40, p. 15181-15205Article in journal (Refereed) Published
Abstract [en]

Traditional paper and papermaking have struggled with a declining market during the last decades. However, the incorporation of nanotechnology in papermaking has brought possibilities to develop low-cost, biocompatible and flexible products with sophisticated functionalities. The functionality of nanopapers emerges from the intrinsic properties of the nanofibrous network, the additional loading of specific nanomaterials, or the additional deposition and patterning of thin films of nanomaterials on the paper surface. A successful development of functional nanopapers requires understanding in how the nanopaper matrix, nanomaterial fillers, coating pigments/inks, functional additives and manufacturing processes all interact to provide the intended functionality. This review addresses the emerging area of functional nanopapers. The review discusses flexible and multifunctional nanopapers, nanomaterials being used in nanopaper making, manufacturing techniques, and functional applications that provide new important possibilities to utilize papermaking technology. The interface where nanomaterials research meets traditional papermaking has important implications for food packaging, energy harvesting, and energy storage, flexible electronics, low-cost devices for medical diagnostics, and numerous other areas.

National Category
Materials Chemistry
Identifiers
urn:nbn:se:miun:diva-31630 (URN)10.1039/C7NR04656A (DOI)000413905200001 ()28990609 (PubMedID)2-s2.0-85031894512 (Scopus ID)
Available from: 2017-09-15 Created: 2017-09-15 Last updated: 2017-12-15Bibliographically approved
Öhlund, T., Hummelgård, M. & Olin, H. (2017). Sintering Inhibition of Silver Nanoparticle Films via AgCl Nanocrystal Formation. Nanomaterials, 7(8), Article ID 224.
Open this publication in new window or tab >>Sintering Inhibition of Silver Nanoparticle Films via AgCl Nanocrystal Formation
2017 (English)In: Nanomaterials, ISSN 2079-4991, Vol. 7, no 8, article id 224Article in journal (Refereed) Published
Abstract [en]

Electrically conductive films are key components in most printed and flexible electronics applications. For the solution processing of conductive films, inks containing silver nanoparticles (AgNPs) remain important because of their relatively easy processing and generally low resistivity after a sintering procedure. Because the commonly used, moderate sintering temperatures of 150-300 °C are still too high for most low-cost flexible substrates, expanding the knowledge of surface-ink interactions that affect the sintering temperature is desirable. It is known that chloride ions can assist the sintering of AgNP films by displacing capping agents on the surfaces of AgNPs. However, very little is known about other possible Cl-AgNP interactions that affect the resistivity and no interaction having the opposite effect (sintering inhibition) has been identified before. Here we identify such a Cl-AgNP interaction giving sintering inhibition and find that the mechanism involves the formation of AgCl nanocrystals within the AgNP film. The AgCl formation was observed after inkjet-printing of AgNP inks with polyvinylpyrrolidone (PVP) as the capping agent onto papers with quick-absorbing coatings containing 0.3 wt % KCl. Our findings show that chloride can have opposite roles during sintering, either assisting or inhibiting the sintering depending on the prevalence of AgCl formation. The prevalence of AgCl formation depends on the absorption properties and the capping agent.

Keywords
chemical sintering, flexible electronics, flexible substrates, inkjet printing, paper coatings, papers, printed electronics, silver nanoparticles, sintering, thin films
National Category
Materials Chemistry
Identifiers
urn:nbn:se:miun:diva-31489 (URN)10.3390/nano7080224 (DOI)000408759500030 ()2-s2.0-85027834420 (Scopus ID)
Available from: 2017-08-28 Created: 2017-08-28 Last updated: 2017-11-29Bibliographically approved
Öhlund, T., Schuppert, A., Andres, B., Andersson, H., Forsberg, S., Schmidt, W., . . . Olin, H. (2015). Assisted sintering of silver nanoparticle inkjet inks on paper with active coatings. RSC Advances, 5, 64841-64849
Open this publication in new window or tab >>Assisted sintering of silver nanoparticle inkjet inks on paper with active coatings
Show others...
2015 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, p. 64841-64849Article in journal (Refereed) Published
Abstract [en]

Inkjet-printed metal films are important within the emerging field of printed electronics. For large-scale manufacturing, low-cost flexible substrates and low temperature sintering is desired. Tailored coated substrates are interesting for roll-to-roll fabrication of printed electronics, since a suitable tailoring of the ink-substrate system may reduce, or remove, the need for explicit sintering. Here we utilize specially designed coated papers, containing chloride as an active sintering agent. The built-in sintering agent greatly assists low-temperature sintering of inkjet-printed AgNP films. Further, we examine the effect of variations in coating pore size and precoating type. Interestingly, we find that the sintering is substantially affected by these parameters.

Keywords
printed electronics, sintering, inkjet printing, silver nanoparticles, AgNP, thin films, paper, coatings, chemical sintering, mesoporous, flexible electronics
National Category
Materials Engineering Nano Technology Materials Chemistry Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-23418 (URN)10.1039/c5ra06626c (DOI)000359136500003 ()2-s2.0-84938717754 (Scopus ID)STC (Local ID)STC (Archive number)STC (OAI)
Available from: 2014-11-13 Created: 2014-11-13 Last updated: 2017-12-05Bibliographically approved
Öhlund, T., Schuppert, A., Hummelgård, M., Bäckström, J., Nilsson, H.-E. & Olin, H. (2015). Inkjet Fabrication of Copper Patterns for Flexible Electronics: Using Paper with Active Precoatings. ACS Applied Materials and Interfaces, 7(33), 18273-18282
Open this publication in new window or tab >>Inkjet Fabrication of Copper Patterns for Flexible Electronics: Using Paper with Active Precoatings
Show others...
2015 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 33, p. 18273-18282Article in journal (Refereed) Published
Abstract [en]

Low-cost solution-processing of highly conductive films is important for the expanding market of printed electronics. For roll-to-roll manufacturing, suitable flexible substrates and compatible postprocessing are essential. Here, custom-developed coated papers are demonstrated to facilitate the inkjet fabrication of high performance copper patterns. The patterns are fabricated in ambient conditions using water-based CuO dispersion and intense pulsed light (IPL) processing. Papers using a porous CaCO3 precoating, combined with an acidic mesoporous absorption coating, improve the effectiveness and reliability of the IPL process. The processing is realizable within 5 ms, using a single pulse of light. A resistivity of 3.1 ± 0.12 μΩ·cm is achieved with 400 μm wide conductors, corresponding to more than 50% of the conductivity of bulk copper. This is higher than previously reported results for IPL-processed copper.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2015
Keywords
intense pulsed light sintering, flash light sintering, printed flexible electronics, inkjet printing, paper coatings, copper patterns, IPL sintering, IPL processing, paper electronics, CuO reduction, inkjet fabrication
National Category
Physical Chemistry Materials Engineering Nano Technology Materials Chemistry Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-23419 (URN)10.1021/acsami.5b03061 (DOI)000360322000012 ()2-s2.0-84940528167 (Scopus ID)STC (Local ID)STC (Archive number)STC (OAI)
Available from: 2014-11-13 Created: 2014-11-13 Last updated: 2017-12-05Bibliographically approved
Öhlund, T. (2014). Metal Films for Printed Electronics: Ink-substrate Interactions and Sintering. (Doctoral dissertation). Sundsvall: Mid Sweden University
Open this publication in new window or tab >>Metal Films for Printed Electronics: Ink-substrate Interactions and Sintering
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

A new manufacturing paradigm may lower the cost and environmental impact of existing products, as well as enable completely new products. Large scale, roll-to-roll manufacturing of flexible electronics and other functionality has great potential. However, a commercial breakthrough depends on a lower consumption of materials and energy compared with competing alternatives, and that sufficiently high performance and reliability of the products can be maintained. The substrate constitutes a large part of the product, and therefore its cost and environmental sustainability are important. Electrically conducting thin films are required in many functional devices and applications. In demanding applications, metal films offer the highest conductivity.

 

In this thesis, paper substrates of various type and construction were characterized, and the characteristics were related to the performance of inkjet-printed metal patterns. Fast absorption of the ink carrier was beneficial for well-defined pattern geometry, as well as high conductivity. Surface roughness with topography variations of sufficiently large amplitude and frequency, was detrimental to the pattern definition and conductivity. Porosity was another important factor, where the characteristic pore size was much more important than the total pore volume. Apparent surface energy was important for non-absorbing substrates, but of limited importance for coatings with a high absorption rate. Applying thin polymer–based coatings on flexible non-porous films to provide a mechanism for ink solvent removal, improved the pattern definition significantly. Inkjet-printing of a ZnO-dispersion on uncoated paper provided a thin spot-coating, allowing conductivity of silver nanoparticle films. Conductive nanoparticle films could not form directly on the uncoated paper.

 

The resulting performance of printed metal patterns was highly dependent on a well adapted sintering methodology. Several sintering methods were examined in this thesis, including conventional oven sintering, electrical sintering, microwave sintering, chemical sintering and intense pulsed light sintering. Specially designed coated papers with modified chemical and physical properties, were utilized for chemical low-temperature sintering of silver nanoparticle inks. For intense pulsed light sintering and material conversion of patterns, custom equipment was designed and built. Using the equipment, inkjet-printed copper oxide patterns were processed into highly conducting copper patterns. Custom-designed papers with mesoporous coatings and porous precoatings improved the reliablility and performance of the reduction and sintering process.

 

 

 

 

The thesis aims to clarify how ink-substrate interactions and sintering methodology affect the performance and reliability of inkjet-printed nanoparticle patterns on flexible substrates. This improves the selection, adaptation, design and manufacturing of suitable substrates for inkjet-printed high conductivity patterns, such as circuit boards or RFID antennas.  

Place, publisher, year, edition, pages
Sundsvall: Mid Sweden University, 2014. p. 72
Series
Mid Sweden University doctoral thesis, ISSN 1652-893X ; 210
Keywords
inkjet printing, silver nanoparticles, paper, flexible substrates, sintering, printed electronics, IPL sintering, flash sintering, copper films, coatings, thin films, AgNP, conductive films, metal films
National Category
Physical Chemistry Materials Engineering Nano Technology Physical Sciences
Identifiers
urn:nbn:se:miun:diva-23420 (URN)978-91-87557-98-9 (ISBN)
Public defence
2014-12-18, Mediacenter, Digital Printing Center, Järnvägsgatan 3, Örnsköldsvik, 10:00 (English)
Opponent
Supervisors
Available from: 2014-11-14 Created: 2014-11-13 Last updated: 2015-03-13Bibliographically approved
Zhang, R., Andersson, H., Andersson, M., Andres, B., Edström, P., Edvardsson, S., . . . Olin, H. (2013). High-speed deposition of multilayer nanofilms using soap-film coating. In: : . Paper presented at 19th International Vacuum Congress (IVC-19), Paris, France, September 9-13 2013.
Open this publication in new window or tab >>High-speed deposition of multilayer nanofilms using soap-film coating
Show others...
2013 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

High-speed deposition of multilayer nanofilms using soap-film coating

Renyun Zhang, Henrik A. Andersson, Mattias Andersson, Britta Andres, Per Edström, Sverker Edvardsson, Sven Forsberg, Magnus Hummelgård, Niklas Johansson, Kristoffer Karlsson, Hans-Erik Nilsson, Martin Olsen, Tetsu Uesaka, Thomas Öhlund & Håkan Olin

Department of Applied Science and Design, Mid Sweden University, SE-85170 Sundsvall, Sweden

Email: renyun.zhang@miun.se or hakan.olin@miun.se

Coating1 of thin films is of importance for making functionalized surfaces with applications in many fields from electronics to consumer packaging. To decrease the cost, large scale roll-to-roll2 coating techniques are usually done at high speed, for example, ordinary printing paper is coated at a speed of tens of meters per second by depositing micrometer thick layers of clay. However, nanometer thin films are harder to coat at high speed by wet-chemical methods, requiring special roll-to-roll vacuum techniques3 with the cost of higher complexity.

Here, we report a simple wet chemical method for high-speed coating of films down to molecular thicknesses, called soap-film coating (SFC)4. The technique is based on forcing a substrate through a soap film that contains nanomaterials. In the simplest laboratory version, the films can be deposited by a hand-coating procedure set up in a couple of minutes. The method is quite general molecules or nanomaterials or sub-micrometer materials (Figure 1) with thicknesses ranging from less than a monolayer to several layers at speeds up to meters per second. The applications of soap-film coating is quite wide an we will show solar cells, electrochromic devices, optical nanoparticle crystals, and nano-film devices. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology.

Fig. 1. Soap film coating of nanoparticles, layered materials, nanowires, and molecules. a sub-monolayer 240 nm silica nanoparticle (scale bar 2 µm) b monolayer c double layer. d monolayer gold nanoparticles. e single layer TiO2 nanoparticles. f sub-monolayer polystyrene (scale 2 µm), g monolayer of polystyrene. h triple-layer of polystyrene. i monolayer of Ferritin.  j AFM image of <1.5 layer GO film (3 µm x 2 µm). k clay on glass (scale 2 µm). l SFC coated nanocellulose. m Absorbance spectra Rhodamine B on a glass slide. AFM of SDS layers n (2 µm x 1.5 µm) and o (20 µm x 15 µm).

References

  1. Tracton, A. A. Coating Technology Handbook (CRC Press, Boca Raton, 2006).

  2. Ohring, M. Materials science of thin films. (Academic press., 2001).

  3. Charles, B. Vacuum deposition onto webs, films and foils. (William Andrew, 2011).

Zhang, R. Y., Andersson, H. A., Andersson, M., Andres, B., Edström, P., Edvardsson, S., Forsberg, S., Hummelgård, M., Johansson, N., Karlsson, K., Nilsson, H.-E., Olsen, M., Uesaka, T., Öhlund, T., Olin H. Soap film coating: High-speed deposition of multilayer nanofilms. Submitted.

National Category
Natural Sciences
Identifiers
urn:nbn:se:miun:diva-20338 (URN)STC (Local ID)STC (Archive number)STC (OAI)
Conference
19th International Vacuum Congress (IVC-19), Paris, France, September 9-13 2013
Available from: 2013-11-27 Created: 2013-11-27 Last updated: 2016-10-20Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-2340-2363

Search in DiVA

Show all publications