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Haraldsson, Klas TommyORCID iD iconorcid.org/0000-0002-0441-6893
Alternative names
Publications (10 of 90) Show all publications
Sticker, D., Rothbauer, M., Ehgartner, J., Steininger, C., Liske, O., Liska, R., . . . Ertl, P. (2019). Oxygen Management at the Microscale: A Functional Biochip Material with Long-Lasting and Tunable Oxygen Scavenging Properties for Cell Culture Applications. ACS Applied Materials and Interfaces, 11(10), 9730-9739
Open this publication in new window or tab >>Oxygen Management at the Microscale: A Functional Biochip Material with Long-Lasting and Tunable Oxygen Scavenging Properties for Cell Culture Applications
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2019 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 10, p. 9730-9739Article in journal (Refereed) Published
Abstract [en]

Oxygen plays a pivotal role in cellular homeostasis, and its partial pressure determines cellular function and fate. Consequently, the ability to control oxygen tension is a critical parameter for recreating physiologically relevant in vitro culture conditions for mammalian cells and microorganisms. Despite its importance, most microdevices and organ-on-a-chip systems to date overlook oxygen gradient parameters because controlling oxygen often requires bulky and expensive external instrumental setups. To overcome this limitation, we have adapted an off-stoichiometric thiol-ene-epoxy polymer to efficiently remove dissolved oxygen to below 1 hPa and also integrated this modified polymer into a functional biochip material. The relevance of using an oxygen scavenging material in microfluidics is that it makes it feasible to readily control oxygen depletion rates inside the biochip by simply changing the surface-to-volume aspect ratio of the microfluidic channel network as well as by changing the temperature and curing times during the fabrication process.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
Keywords
oxygen control, oxygen scavenging, thiol-ene, functional material, bacteria, mammalian cells
National Category
Textile, Rubber and Polymeric Materials
Identifiers
urn:nbn:se:kth:diva-248344 (URN)10.1021/acsami.8b19641 (DOI)000461538000010 ()30747515 (PubMedID)2-s2.0-85062816786 (Scopus ID)
Note

QC 20190409

Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2019-04-09Bibliographically approved
Zandi Shafagh, R., Decrop, D., Ven, K., Vanderbeke, A., Hanusa, R., Breukers, J., . . . van der Wijngaart, W. (2019). Reaction Injection Molding of Hydrophilic-in-Hydrophobic Femtolitre-Well Arrays. Microsystems & Nanoengineering (5), Article ID 25.
Open this publication in new window or tab >>Reaction Injection Molding of Hydrophilic-in-Hydrophobic Femtolitre-Well Arrays
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2019 (English)In: Microsystems & Nanoengineering, E-ISSN 2055-7434, no 5, article id 25Article in journal (Refereed) Published
Abstract [en]

Patterning of micro- and nanoscale topologies and surface properties of polymer devices is of particular importance for a broad range of life science applications, including cell-adhesion assays and highly sensitive bioassays. The manufacturing of such devices necessitates cumbersome multiple-step fabrication procedures and results in surface properties which degrade over time. This critically hinders their wide-spread dissemination. Here, we simultaneously mold and surface energy pattern microstructures in off-stoichiometric thiol-ene by area-selective monomer self-assembly in a rapid micro-reaction injection molding cycle. We replicated arrays of 1,843,650 hydrophilic-in-hydrophobic femtolitre-wells with long-term stable surface properties and magnetically trapped beads with 75% and 87.2% efficiency in single- and multiple-seeding events, respectively. These results form the basis for ultrasensitive digital biosensors, specifically, and for the fabrication of medical devices and life science research tools, generally.

Place, publisher, year, edition, pages
Nature Publishing Group, 2019
Keywords
Reaction injection molding
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-248300 (URN)10.1038/s41378-019-0065-2 (DOI)000470930600001 ()2-s2.0-85066487508 (Scopus ID)
Note

QC 20190405

Available from: 2019-04-04 Created: 2019-04-04 Last updated: 2020-03-09Bibliographically approved
Yasuga, H., Guo, W., Hansson, J., Haraldsson, T., Miki, N. & van der Wijngaart, W. (2018). Droplet microfluidics inside paper. In: 2018 IEEE Micro Electro Mechanical Systems (MEMS): . Paper presented at 31st IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2018, Belfast, United Kingdom, 21 January 2018 through 25 January 2018 (pp. 269-271). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Droplet microfluidics inside paper
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2018 (English)In: 2018 IEEE Micro Electro Mechanical Systems (MEMS), Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 269-271Conference paper, Published paper (Refereed)
Abstract [en]

Here, we demonstrate, for the first time: the self-digitization, i.e. spontaneous formation, of microdroplets during the imbibition of paper; the on-demand merging of individual microdroplets in paper; and the on-demand ejection of individual microdroplets from the paper. Two technical novelties underlie these novel functions: the formation of free-standing synthetic microfluidic paper, i.e. a porous matrix of slanted and interconnected micropillars without bottom layer; and the hydrophobic surface modification of the paper. The ease of manipulation and the direct access to the microdroplets from the environment makes this an extremely versatile tool, with potential applications in liquid sample digitisation and microparticle generation.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2018
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:kth:diva-228552 (URN)10.1109/MEMSYS.2018.8346536 (DOI)000434960900071 ()2-s2.0-85047016277 (Scopus ID)9781538647820 (ISBN)
Conference
31st IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2018, Belfast, United Kingdom, 21 January 2018 through 25 January 2018
Note

QC 20180528

Available from: 2018-05-28 Created: 2018-05-28 Last updated: 2020-03-16Bibliographically approved
Shafagh, R. Z., Vastesson, A., Guo, W., van der Wijngaart, W. & Haraldsson, K. T. (2018). E-Beam Nanostructuring and Direct Click Biofunctionalization of Thiol–Ene Resist. ACS Nano, 12(10), 9940-9946
Open this publication in new window or tab >>E-Beam Nanostructuring and Direct Click Biofunctionalization of Thiol–Ene Resist
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2018 (English)In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, no 10, p. 9940-9946Article in journal (Refereed) Published
Abstract [en]

Electron beam lithography (EBL) is of major importance for ultraminiaturized biohybrid system fabrication, as it allows combining biomolecular patterning and mechanical structure definition on the nanoscale. Existing methods are limited by multistep biomolecule immobilization procedures, harsh processing conditions that are harmful to sensitive biomolecules, or the structural properties of the resulting protein monolayers or hydrogel-based resists. This work introduces a thiol-ene EBL resist with chemically reactive thiol groups on its native surface that allow the direct and selective "click" immobilization of biomolecules under benign processing conditions. We constructed EBL structured features of size down to 20 nm, and direct functionalized the nanostructures with a sandwich of biotin and streptavidin. The facile combination of polymer nanostructuring with biomolecule immobilization enables mechanically robust biohybrid components of interest for nanoscale biomedical, electronic, photonic, and robotic applications.

Keywords
OSTE; biohybrid; e-beam; nanoscale; NEMS; protein patterning; resist; thiol−ene
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-236089 (URN)10.1021/acsnano.8b03709 (DOI)000448751800030 ()30212184 (PubMedID)2-s2.0-8505371109 (Scopus ID)
Note

QC 20181114

Available from: 2018-10-16 Created: 2018-10-16 Last updated: 2020-03-16Bibliographically approved
Zhou, X., Haraldsson, K. T., Nania, S., Ribet, F., Palano, G., Heuchel, R., . . . van der Wijngaart, W. M. (2018). Human Cell Encapsulation in Gel Microbeads with Cosynthesized Concentric Nanoporous Solid Shells. Advanced Functional Materials, 28(21), Article ID 1707129.
Open this publication in new window or tab >>Human Cell Encapsulation in Gel Microbeads with Cosynthesized Concentric Nanoporous Solid Shells
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2018 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 21, article id 1707129Article in journal (Refereed) Published
Abstract [en]

Encapsulation of therapeutic cells in core-shell microparticles has great promise for the treatment of a range of health conditions. Unresolved challenges related to control of the particle morphology, mechanical stability, and immunogenicity hinder dissemination of this promising approach. Here, a novel polymer material for cell encapsulation and a combined novel, easy to control, synthesis method are introduced. Core-shell cell encapsulation is demonstrated with a concentric core-shell morphology formed during a single UV exposure, resulting in particles that consist of a synthetic hydrogel core of polyethylene glycol diacrylate and a solid, but porous, shell of off-stoichiometric thiol-ene. The encapsulated human cells in 100 mu m diameter particles have >90% viability. The average shell thickness is controlled between 7 and 13 mu m by varying the UV exposure, and the shell is measured to be permeable to low molecular weight species (<180 Da) but impermeable to higher molecular weight species (>480 Da). The unique material properties and the orthogonal control of the microparticle core size, shell thickness, shell permeability, and shell surface properties address the key unresolved challenges in the field, and are expected to enable faster translation of novel cell therapy concepts from research to clinical practice.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2018
Keywords
cell encapsulation, cell therapy, droplet microfluidics, off-stoichiometry thiol-ene polymers, OSTE, PEGDA, poly(ethylene glycol) diacrylate
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-231217 (URN)10.1002/adfm.201707129 (DOI)000434030500006 ()2-s2.0-85045190003 (Scopus ID)
Note

QC 20180628

Available from: 2018-06-28 Created: 2018-06-28 Last updated: 2018-06-28Bibliographically approved
Haraldsson, K. T. (2018). Synthetic paper - a microstructured coating developed for medical diagnostics. Paper presented at 256th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nanoscience, Nanotechnology and Beyond, AUG 19-23, 2018, Boston, MA. Abstract of Papers of the American Chemical Society, 256
Open this publication in new window or tab >>Synthetic paper - a microstructured coating developed for medical diagnostics
2018 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 256Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-238548 (URN)000447609104486 ()
Conference
256th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nanoscience, Nanotechnology and Beyond, AUG 19-23, 2018, Boston, MA
Note

QC 20181105

Available from: 2018-11-05 Created: 2018-11-05 Last updated: 2018-11-05Bibliographically approved
Lobov, G., Marinins, A., Shafagh, R. Z., Zhao, Y., van der Wijngaart, W., Wosinski, L., . . . Popov, S. (2017). Electro-optical effects of high aspect ratio P3HT nanofibers colloid in polymer micro-fluid cells. Optics Letters, 42(11), 2157-2160
Open this publication in new window or tab >>Electro-optical effects of high aspect ratio P3HT nanofibers colloid in polymer micro-fluid cells
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2017 (English)In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 42, no 11, p. 2157-2160Article in journal (Refereed) Published
Abstract [en]

This Letter reports the electro-optical (EO) effect of Poly(3-hexylthiophene-2,5-diyl) (P3HT) nanofibers colloid in a polymer micro-fluidic EO cell. P3HT nanofibers are high aspect ratio semiconducting nanostructures, and can be collectively aligned by an external alternating electric field. Optical transmission modulated by the electric field is a manifestation of the electro-optical effect due to high inner crystallinity of P3HT nanofibers. According to our results, the degree of alignment reaches a maximum at 0.6 V/μm of electric field strength, implying a big polarizability value due to geometry and electrical properties of P3HT nanofibers. We believe that one-dimensional crystalline organic nanostructures have a large potential in EO devices due to their significant anisotropy, wide variety of properties, low actuation voltages, and opportunity to be tailored via adjustment of the fabrication process.

Place, publisher, year, edition, pages
OSA Publishing, 2017
Keywords
P3HT, Nanofibers, optofluidics, reaction injectin molding, RIM, OSTE, micro-fluid cells
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-207850 (URN)10.1364/OL.42.002157 (DOI)000403534700027 ()28569870 (PubMedID)2-s2.0-85020417115 (Scopus ID)
Note

QC 20170613

Available from: 2017-05-27 Created: 2017-05-27 Last updated: 2020-03-09Bibliographically approved
Rahiminejad, S., Hansson, J., Kohler, E., van der Wijngaart, W., Haraldsson, K. T., Haasl, S. & Enoksson, P. (2017). Rapid manufacturing of OSTE polymer RF-MEMS components. In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS): . Paper presented at 30th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2017, 22 January 2017 through 26 January 2017 (pp. 901-904). IEEE
Open this publication in new window or tab >>Rapid manufacturing of OSTE polymer RF-MEMS components
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2017 (English)In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), IEEE, 2017, p. 901-904Conference paper, Published paper (Refereed)
Abstract [en]

This paper reports the first RF-MEMS component in OSTE polymer. Three OSTE-based ridge gap resonators were fabricated by direct, high aspect ratio, photostructuring. The OSTE polymer's good adhesion to gold makes it suitable for RF-MEMS applications. The OSTE ridge gap resonators differ in how they were coated with gold. The OSTE-based devices are compared to each other as well as to Si-based, SU8-based, and CNT-based devices of equal design. The OSTE-based process was performed outside the cleanroom, and with a fast fabrication process (∼1 h). The OSTE-based device performance is on par with that of the other alternatives in terms of frequency, attenuation, and Q-factor.

Place, publisher, year, edition, pages
IEEE, 2017
Keywords
Aspect ratio, Gold, Gold coatings, Mechanics, Polymers, Q factor measurement, Resonators, Device performance, Fabrication process, High aspect ratio, Q-factors, Rapid manufacturing, RF-MEMS, Si-based, MEMS
National Category
Textile, Rubber and Polymeric Materials
Identifiers
urn:nbn:se:kth:diva-207992 (URN)10.1109/MEMSYS.2017.7863554 (DOI)000402552000231 ()2-s2.0-85015753569 (Scopus ID)9781509050789 (ISBN)
Conference
30th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2017, 22 January 2017 through 26 January 2017
Note

QC 20170607

Available from: 2017-06-07 Created: 2017-06-07 Last updated: 2020-03-05Bibliographically approved
Decrop, D., Pardon, G., Brancato, L., Kil, D., Zandi Shafagh, R., Kokalj, T., . . . Lammertyn, J. (2017). Single-step imprinting of femtoliter microwell arrays allows digital bioassays with attomolar limit of detection. ACS Applied Materials and Interfaces
Open this publication in new window or tab >>Single-step imprinting of femtoliter microwell arrays allows digital bioassays with attomolar limit of detection
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2017 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252Article in journal (Refereed) Published
Abstract [en]

Bead-based microwell array technology is growing as an ultrasensitive target detection tool. However, dissemination of the technology and its commercial use are hampered by current fabrication methods for hydrophilic-in-hydrophobic microwell arrays, which are either expensive or labour-intensive to manufacture, or which results in low bead seeding efficiencies. In this paper, we present a novel single-step manufacturing method for imprinting cheap and disposable hydrophilic-in-hydrophobic microwell arrays suitable for single-molecule detection. Single-step imprinting of hydrophilic-in-hydrophobic microwell arrays is made possible using an innovative surface energy replication approach by means of a hydrophobic thiol-ene polymer formulation. In this polymer, hydrophobic-moiety-containing monomers self-assemble against the hydrophobic surface of the imprinting stamp, which results in a hydrophobic replica surface after polymerization. After removing the stamp, hydrophilic wells are obtained with the well bottoms consisting of glass substrate. We demonstrate that the hydrophilic-in-hydrophobic imprinted microwell arrays enable successful and efficient self-assembly of individual water droplets and seeding of magnetic beads with loading efficiencies up to 96%. We also demonstrate the suitability of the microwell arrays for the isolation and detection of single-molecules achieving a limit of detection of 17.4 aM when performing a streptavidin-biotin binding assay. The ease of manufacturing demonstrated here is expected to allow translation of digital microwell array technology towards diagnostic applications.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2017
Keywords
digital bioassays, limit of detection, hydrophilic-in-hydrophobic, polymer, OSTE+, OSTEMER
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-202934 (URN)10.1021/acsami.6b15415 (DOI)000398246900013 ()28266828 (PubMedID)2-s2.0-85016584924 (Scopus ID)
Note

QC 20170310

Available from: 2017-03-07 Created: 2017-03-07 Last updated: 2020-03-09Bibliographically approved
Hansson, J., Yasuga, H., Haraldsson, K. T. & van der Wijngaart, W. (2017). Synthetic paper. us 20170351175A1.
Open this publication in new window or tab >>Synthetic paper
2017 (English)Patent (Other (popular science, discussion, etc.))
Abstract [en]

A synthetic paper is manufactured with a method comprising the steps of: a) providing at least two types of pho to-polymerizable monomers, b) exposing the volume to a three-dimensional light pattern to induce a polymerization reaction, and c) removing uncured monomer to create an open microstructure. The volume comprises at least one monomer comprising at least two thiol groups and at least one monomer comprising at least two carbon-carbon double bonds, where the ratio (r1) between the number of thiol groups and the number of carbon-carbon double bonds fulfils one of: 0.5≦r1≦0.9 and 1.1≦r1≦2. One advantage is that off stoichiometry creates an edge effect giving better defined boundaries between exposed and unexposed parts in the volume and giving a possibility to create thinner micro pillars. Another advantage is that it is easy to bind molecules to the surface to obtain desired surface properties.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-264845 (URN)
Patent
US 20170351175A1
Note

QC 20191211

Available from: 2019-12-04 Created: 2019-12-04 Last updated: 2019-12-11Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-0441-6893

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