kth.sePublications
Change search
Link to record
Permanent link

Direct link
Alternative names
Publications (10 of 903) Show all publications
He, Z., Chen, F. & He, S. (2024). Fabrication of microneedles using two photon-polymerization with low numerical aperture. Optics Communications, 553, Article ID 130093.
Open this publication in new window or tab >>Fabrication of microneedles using two photon-polymerization with low numerical aperture
2024 (English)In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 553, article id 130093Article in journal (Refereed) Published
Abstract [en]

Three-dimensional (3D) micro-nano fabrication through two-photon polymerization (TPP) is a prominent approach for fabricating complex 3D structures. However, the existing techniques face limitations, such as small fabrication area, dependence on high numerical aperture (e.g., oil immersion) objective lenses, which are more expensive. We developed a 780 nm fs laser system integrated with a 2D galvanometer system and Z axis to create a 3D micro-nano printing system. A method to print arbitrarily complex 3D structures while maintaining an extremely high lateral spatial resolution of sub-100nm is proposed by using a cheap low numerical aperture objective lens with the laser power and exposure time precisely controlled. The impact of the laser power and exposure time on the resolution of 3D micro-nano processing is investigated, and we identify the optimal processing environment for achieving the best resolution. The printed linewidth of 62 nm was achieved without the use of an oil immersed objective lens, and only one laser beam was used instead of stimulated emission depletion. Microneedle arrays for animal injection were fabricated using this strategy, which can improve the performance of animal organoid repair. Our results suggest that TPP micro-nano fabrication is an effective method for processing microneedle arrays for biomedical engineering, with the ability to improve the processing resolution with a cheap low numerical aperture objectives lens (e.g., NA = 0.4) through meticulous control of laser power and exposure time. This approach opens up possibilities for affordable and scalable fabrication in sub-100nm structures.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
3D printing, Femtosecond laser, Micro-nano fabrication, Microneedles, Two-photon polymerization
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-340319 (URN)10.1016/j.optcom.2023.130093 (DOI)001165242400001 ()2-s2.0-85177071702 (Scopus ID)
Note

QC 20240301

Available from: 2024-01-08 Created: 2024-01-08 Last updated: 2024-03-01Bibliographically approved
Wang, N., Yang, A., Tian, X., Liao, J., Yang, Z., Pan, Y., . . . He, S. (2024). Label-free analysis of the β-hydroxybutyricacid drug on mitochondrial redox states repairment in type 2 diabetic mice by resonance raman scattering. Biomedicine and Pharmacotherapy, 172, Article ID 116320.
Open this publication in new window or tab >>Label-free analysis of the β-hydroxybutyricacid drug on mitochondrial redox states repairment in type 2 diabetic mice by resonance raman scattering
Show others...
2024 (English)In: Biomedicine and Pharmacotherapy, ISSN 0753-3322, E-ISSN 1950-6007, Vol. 172, article id 116320Article in journal (Refereed) Published
Abstract [en]

Background: Mitochondrial redox imbalance underlies the pathophysiology of type2 diabetes mellitus (T2DM), and is closely related to tissue damage and dysfunction. Studies have shown the beneficial effects of dietary strategies that elevate β-hydroxybutyrate (BHB) levels in alleviating T2DM. Nevertheless, the role of BHB has not been clearly elucidated. Methods: We performed a spectral study to visualize the preventive effects of BHB on blood and multiorgan mitochondrial redox imbalance in T2DM mice via using label-free resonance Raman spectroscopy (RRS), and further explored the impact of BHB therapy on the pathology of T2DM mice by histological and biochemical analyses. Findings: Our data revealed that RRS-based mitochondrial redox states assay enabled clear and reliable identification of the improvement of mitochondrial redox imbalance by BHB, evidenced by the reduction of Raman peak intensity at 750 cm−1, 1128 cm−1 and 1585 cm−1 in blood, tissue as well as purified mitochondria of db/db mice and the increase of tissue mitochondrial succinic dehydrogenase (SDH) staining after BHB treatment. Exogenous supplementation of BHB was also found to attenuate T2DM pathology related to mitochondrial redox states, involving organ injury, blood glucose control, insulin resistance and systemic inflammation. Interpretation: Our findings provide strong evidence for BHB as a potential therapeutic strategy targeting mitochondria for T2DM.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Label-free, Mitochondrial redox state, Raman spectroscopy, Type 2 diabetes, β-hydroxybutyric acid
National Category
Endocrinology and Diabetes
Identifiers
urn:nbn:se:kth:diva-344192 (URN)10.1016/j.biopha.2024.116320 (DOI)38387134 (PubMedID)2-s2.0-85186090731 (Scopus ID)
Note

QC 20240307

Available from: 2024-03-06 Created: 2024-03-06 Last updated: 2024-03-07Bibliographically approved
Zhang, C., Zheng, K., Li, C., Zhang, R., Zhu, Y., Xia, L., . . . He, S. (2024). Single-Molecule Protein Analysis by Centrifugal Droplet Immuno-PCR with Magnetic Nanoparticles. Analytical Chemistry, 96(5), 1872-1879
Open this publication in new window or tab >>Single-Molecule Protein Analysis by Centrifugal Droplet Immuno-PCR with Magnetic Nanoparticles
Show others...
2024 (English)In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 96, no 5, p. 1872-1879Article in journal (Refereed) Published
Abstract [en]

Detecting proteins in ultralow concentrations in complex media is important for many applications but often relies on complicated techniques. Herein, a single-molecule protein analyzer with the potential for high-throughput applications is reported. Gold-coated magnetic nanoparticles with DNA-labeled antibodies were used for target recognition and separation. The immunocomplex was loaded into microdroplets generated with centrifugation. Immuno-PCR amplification of the DNA enabled the quantification of proteins at the level of single molecules. As an example, ultrasensitive detection of alpha-synuclein, a biomarker for neurodegenerative diseases, is achieved. The limit of detection was determined to be similar to 50 aM in buffer and similar to 170 aM in serum. The method exhibited high specificity and could be used to analyze post-translational modifications such as protein phosphorylation. This study will inspire wider studies on single-molecule protein detection, especially in disease diagnostics, biomarker discovery, and drug development.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:kth:diva-343898 (URN)10.1021/acs.analchem.3c03724 (DOI)001158537700001 ()38225884 (PubMedID)2-s2.0-85183019008 (Scopus ID)
Note

QC 20240226

Available from: 2024-02-26 Created: 2024-02-26 Last updated: 2024-02-26Bibliographically approved
Lin, Z., Huang, D., Cheng, Z., Wu, W., Wai, P. K., Kang, Z. & He, S. (2024). Using Photonic Crystal Microrings to Mitigate Raman-Kerr Effects Competition for Soliton Microcomb Generation. Journal of Lightwave Technology, 42(1), 268-275
Open this publication in new window or tab >>Using Photonic Crystal Microrings to Mitigate Raman-Kerr Effects Competition for Soliton Microcomb Generation
Show others...
2024 (English)In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 42, no 1, p. 268-275Article in journal (Refereed) Published
Abstract [en]

In nonlinear microresonators with strong stimulated Raman scattering effect, it is difficult if not impossible to generate Kerr soliton microcombs with a small free spectral range (FSR) (< 100 GHz) due to the competition between the Raman and Kerr effects. In this article, we overcome this limitation by using odd-period photonic crystal microrings (PCMs). Numerical simulations on the silicon-on-insulator (SOI) PCM show that a small frequency shift (5 GHz) induced by the photonic crystal structure can moderately suppress the Raman effect, such that chaotic microcombs with a small FSR can be generated. With a larger frequency shift (e.g., >= 10 GHz), the Raman effect is significantly suppressed, and the soliton microcombs can be generated. For comparison, without the frequency shift, only Raman lasing can be achieved in a conventional microring. To investigate the applicability of the proposed method in other material platforms, we carried out simulations for the aluminium nitride (AlN) PCM. The results are comparable to those obtained on the SOI PCM. Our method opens a new approach to the generation of small FSR Kerr soliton microcombs in microresonators with strong Raman effect, which is important for expanding the available nonlinear platforms and applications such as telecommunications, radio-frequency photonics, and astronomical spectrographs.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2024
Keywords
Free spectral range (FSR), microcombs, photonic crystal microring (PCM), raman effect
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-342897 (URN)10.1109/JLT.2023.3302514 (DOI)001129777400026 ()2-s2.0-85167825374 (Scopus ID)
Note

QC 20240201

Available from: 2024-02-01 Created: 2024-02-01 Last updated: 2024-02-01Bibliographically approved
Zhang, T., Tian, J., Wang, Y., Fei, C., Zhang, J., Zhang, F., . . . He, S. (2023). 19.02Gbps/25m Underwater Wireless Optical Communication Adopting Probabilistic Constellation Shaping QAM-DMT Transmission. In: 2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings, ACP/POEM 2023: . Paper presented at 2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings, ACP/POEM 2023, Wuhan, China, Nov 4 2023 - Nov 7 2023. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>19.02Gbps/25m Underwater Wireless Optical Communication Adopting Probabilistic Constellation Shaping QAM-DMT Transmission
Show others...
2023 (English)In: 2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings, ACP/POEM 2023, Institute of Electrical and Electronics Engineers (IEEE) , 2023Conference paper, Published paper (Refereed)
Abstract [en]

We experimentally demonstrated probabilistic constellation shaping quadrature amplitude modulation discrete multitone (PCS QAM-DMT) for 25-m underwater wireless optical communication (UWOC) system with a net data rate of 19.02Gbps. 28.1% capacity improvement is achieved in comparison with conventional bit-power loading DMT scheme. To the best of our knowledge, this is the highest net data rate ever reported for a single LD in current UWOC.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
Keywords
laser communication, probabilistic constellation shaping (PCS), underwater wireless optical communication (UWOC)
National Category
Telecommunications Communication Systems
Identifiers
urn:nbn:se:kth:diva-343184 (URN)10.1109/ACP/POEM59049.2023.10369021 (DOI)2-s2.0-85183298482 (Scopus ID)
Conference
2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings, ACP/POEM 2023, Wuhan, China, Nov 4 2023 - Nov 7 2023
Note

 Part of proceedings ISBN 9798350312614

QC 20240212

Available from: 2024-02-08 Created: 2024-02-08 Last updated: 2024-02-29Bibliographically approved
Gong, D., Yan, L., Gu, B., Zhang, R., Mao, X. & He, S. (2023). A Computer-Assisted Diagnosis System for the Detection of Chronic Gastritis in Endoscopic Images Using A Novel Convolution and Relative Self-Attention Parallel Network. IEEE Access, 11, 116990-117003
Open this publication in new window or tab >>A Computer-Assisted Diagnosis System for the Detection of Chronic Gastritis in Endoscopic Images Using A Novel Convolution and Relative Self-Attention Parallel Network
Show others...
2023 (English)In: IEEE Access, E-ISSN 2169-3536, Vol. 11, p. 116990-117003Article in journal (Refereed) Published
Abstract [en]

Chronic gastritis mainly includes chronic non-atrophic gastritis (CNAG), autoimmune gastritis (AIG), and type B gastritis. Early detection of AIG and type B gastritis will help identify high-risk groups for gastric cancer and prevent the development of irreversible peripheral neuropathy. We aim to develop a computer-assisted diagnosis (CADx) system by presenting a novel Convolution and Relative Self-Attention Parallel Network (CRSAPNet). We collected 3576 endoscopic images of chronic gastritis from 205 patients. MBConv and Relative Self-Attention Parallel Block (CRSAPB) was proposed to concatenate local features (such as mucosal folds and mucosal vessels extracted by MBConv) and global features (such as atrophied area extracted by Relative Self-Attention) in parallel in the last two stages of CRSAPNet. The CADx system distinguished AIG from type B gastritis and CNAG. The CRSAPNet achieved the highest overall accuracy of 95.44% (94.65% precision, 93.51% recall, 94.08% F1-score for AIG) with the fewest parameters. We used Grad-CAM to visually analyze the heat maps. We only replaced the original blocks of the third stage of ResNet50 and ConvNeXt-T with CRSAPB, resulting in an overall accuracy improvement of 0.37%, and 4.19%, respectively. Furthermore, the CADx system classified the three types of chronic gastritis for the first time. The CRSAPNet achieved an overall accuracy of 91.62%, and the overall accuracies in the location of the gastric body and gastric fundus were 93.43% and 92.51%, respectively. A new state-of-the-art deep learning network is introduced to distinguish AIG from type B gastritis and CNAG, and a classification for three types of chronic gastritis is reported for the first time.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
Keywords
atrophic gastritis, autoimmune gastritis, chronic gastritis, deep learning, Gastric cancer, self-attention
National Category
Medical Image Processing
Identifiers
urn:nbn:se:kth:diva-339710 (URN)10.1109/ACCESS.2023.3326540 (DOI)001092101900001 ()2-s2.0-85175847434 (Scopus ID)
Note

QC 20231120

Available from: 2023-11-20 Created: 2023-11-20 Last updated: 2024-02-29Bibliographically approved
He, N., Guo, T., Jin, Y. & He, S. (2023). All-in-One Collimating Splitter Based on a Meta-Fiber Platform. Applied Sciences, 13(7), Article ID 4603.
Open this publication in new window or tab >>All-in-One Collimating Splitter Based on a Meta-Fiber Platform
2023 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 13, no 7, article id 4603Article in journal (Refereed) Published
Abstract [en]

The use of array generators has become ubiquitous in various applications such as laser fabrication, face identification, and motion sensing. The Dammann grating, a diffractive optical element, is the mainstream approach for generating uniform spot arrays. However, its limited capability and the contradiction between the performance and the complexity of fabrication hinder its application. To address this issue, an all-in-one collimating splitter based on metasurfaces is theoretically proposed by synthesizing the phase of an inverse-optimized Dammann grating and a collimating lens. Leveraging both the diffraction effect of Dammann grating and the Fourier transformation of the collimating lens, the number of spot arrays can be largely increased with a single lenslet. The proposed design shows a large field of view of 62 degrees x 62 degrees ffi and a high uniformity of 1.29% in generating a spot array of 3 x 3 on a single-fiber platform, confirmed by both the scalar and full-wave simulation. Further, a larger spot array up to 15 x 15 is also derived in the far field by integrating the proposed metasurface on a 5 x 5 fiber array platform, confirmed by the scalar simulation. Our design may be transplanted to the vertical-cavity surface-emitting laser platform, and shows great potential in various applications including face identification and motion sensing.

Place, publisher, year, edition, pages
MDPI AG, 2023
Keywords
metafiber array, Dammann grating, spot array generator, collimating splitter, dielectric metasurface
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-326884 (URN)10.3390/app13074603 (DOI)000969852900001 ()2-s2.0-85152557486 (Scopus ID)
Note

QC 20230515

Available from: 2023-05-15 Created: 2023-05-15 Last updated: 2023-05-15Bibliographically approved
Zhang, Y., Wu, W., Liu, Y. & He, S. (2023). Analysis of a leaky-wave antenna with high scanning rate using microstrip phase delay lines. In: 2023 Photonics and Electromagnetics Research Symposium, PIERS 2023: Proceedings. Paper presented at 2023 Photonics and Electromagnetics Research Symposium, PIERS 2023, Prague, Czechia, Jul 3 2023 - Jul 6 2023 (pp. 1521-1525). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Analysis of a leaky-wave antenna with high scanning rate using microstrip phase delay lines
2023 (English)In: 2023 Photonics and Electromagnetics Research Symposium, PIERS 2023: Proceedings, Institute of Electrical and Electronics Engineers (IEEE) , 2023, p. 1521-1525Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we analyze the microstrip phase delay (PD) lines of different lengths are applied between the unit-cells (UCs) of leaky-wave antenna (LWA). The employment of PD lines can offer the phase compensations (PCs) for each UC, the simulation experiments observed that the PD lines can significantly improve the realized gain of LWA and reduce the operating bandwidth due to longer PD lines exciting the higher order modes of phase constant. Therefore, the scanning rates (SRs), i.e., scanning range divided by operating bandwidth (%), can remarkably increase. Besides, in order to maintain the beam scanning ability of LWA in travelling-wave direction (or longitudinal direction), the PD lines are placed and varied in the lateral direction. The phase constants in the lateral direction component are also proven to be able to excite higher order modes. Benefit from this, the multi-beam LWAs in the lateral direction can be obtained by the PD lines with optimal lengths, and patterns of multi-beam are fixed with the operating frequency changing.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-337817 (URN)10.1109/PIERS59004.2023.10221280 (DOI)2-s2.0-85171989483 (Scopus ID)
Conference
2023 Photonics and Electromagnetics Research Symposium, PIERS 2023, Prague, Czechia, Jul 3 2023 - Jul 6 2023
Note

Part of ISBN 9798350312843

QC 20231009

Available from: 2023-10-09 Created: 2023-10-09 Last updated: 2023-10-12Bibliographically approved
Lei, Q., Luo, Z., Zheng, X., Lu, N., Zhang, Y., Huang, J., . . . He, S. (2023). Broadband transparent and flexible silver mesh for efficient electromagnetic interference shielding and high-quality free-space optical communication. Optical Materials Express, 13(2), 469-483
Open this publication in new window or tab >>Broadband transparent and flexible silver mesh for efficient electromagnetic interference shielding and high-quality free-space optical communication
Show others...
2023 (English)In: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 13, no 2, p. 469-483Article in journal (Refereed) Published
Abstract [en]

A broadband transparent and flexible silver (Ag) mesh is presented experimentally for the first time for both efficient electromagnetic interference (EMI) shielding in the X band and high-quality free-space optical (FSO) communication. High transmission is achieved in a broad wavelength range of 0.4-2.0 mu m. The transmittance of the Ag mesh relative to the substrate is around 92% and the sheet resistance is as low as 7.12 ohm/sq. The Ag mesh/polyethylene (PE) achieves a high average EMI shielding effectiveness (SE) of 28.8 dB in the X band with an overall transmittance of 80.9% at 550 nm. High-quality FSO communication with small power penalty is attributed to the high optical transmittance and the low haze at 1550 nm, superior to those of the Ag NW networks. With a polydimethylsiloxane (PDMS) coating, the average EMI SE is still up to 26.2 dB and the overall transmittance is increased to 84.5% at 550 nm due to antireflection. The FSO communication does not change much due to the nearly unchanged optical property at 1550 nm. Both the EMI shielding performance and the FSO communication function maintain after 2-hour chemical corrosions as well as after 1000 bending cycles and twisting. Our PDMS/Ag mesh/PE sandwiched film can be self-cleaned, suitable for outdoor applications.

Place, publisher, year, edition, pages
Optica Publishing Group, 2023
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-327192 (URN)10.1364/OME.478830 (DOI)000974409900007 ()2-s2.0-85147429279 (Scopus ID)
Note

QC 20230523

Available from: 2023-05-23 Created: 2023-05-23 Last updated: 2023-05-23Bibliographically approved
Zhang, Z., Guo, T., Lin, Z., Liu, Z., He, N., Xu, X., . . . He, S. (2023). Customized Structural Color Filters by Pixel-Level Electrothermal Regulation. Laser & Photonics reviews, 17(5), Article ID 2200820.
Open this publication in new window or tab >>Customized Structural Color Filters by Pixel-Level Electrothermal Regulation
Show others...
2023 (English)In: Laser & Photonics reviews, ISSN 1863-8880, E-ISSN 1863-8899, Vol. 17, no 5, article id 2200820Article in journal (Refereed) Published
Abstract [en]

Reflective structural colors have backlight-free supremacy and can provide energy-efficient and environmental-friendly color production for many applications. However, they are hindered by the complex process and incorrect colors after fabrication. Here, a pixelated electrothermal oxidation technique is proposed that can precisely tailor and produce reflective structural colors covering the entire visible range, providing the possibility for customized structural color filter arrays from a titanium canvas. Furthermore, as a demonstration, a photonic-firework-like color filter array is achieved in a single step via thermal engineering. Based on this one-step-forming color array, a computational spectrometer is also realized featuring a resolvability of 10 nm and operating bandwidth covering the whole visible range. Considering its compactness and mass production capability, this method has numerous potential applications in, e.g., imaging, anti-counterfeiting, printing, color display, and spectroscopy.

Place, publisher, year, edition, pages
Wiley, 2023
Keywords
color trimming, computational reconstruction, electrothermal, spectrometers, structural colors
National Category
Computer Sciences
Identifiers
urn:nbn:se:kth:diva-330028 (URN)10.1002/lpor.202200820 (DOI)000928686900001 ()2-s2.0-85147530395 (Scopus ID)
Note

QC 20230628

Available from: 2023-06-28 Created: 2023-06-28 Last updated: 2023-06-28Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-3401-1125

Search in DiVA

Show all publications