Hanwei Wang

All Publications

• Visualizing ultrafast photothermal dynamics with decoupled optical force nanoscopy. Nature communications Wang, H., Meyer, S. M., Murphy, C. J., Chen, Y. S., Zhao, Y. 2023; 14 (1): 7267

  Abstract

  The photothermal effect in nanomaterials, resulting from resonant optical absorption, finds wide applications in biomedicine, cancer therapy, and microscopy. Despite its prevalence, the photothermal effect in light-absorbing nanoparticles has typically been assessed using bulk measurements, neglecting near-field effects. Beyond standard imaging and therapeutic uses, nanosecond-transient photothermal effects have been harnessed for bacterial inactivation, neural stimulation, drug delivery, and chemical synthesis. While scanning probe microscopy and electron microscopy offer single-particle imaging of photothermal fields, their slow speed limits observations to milliseconds or seconds, preventing nanoscale dynamic investigations. Here, we introduce decoupled optical force nanoscopy (Dofn), enabling nanometer-scale mapping of photothermal forces by exploiting unique phase responses to temporal modulation. We employ the photothermal effect's back-action to distinguish various time frames within a modulation period. This allows us to capture the dynamic photothermal process of a single gold nanorod in the nanosecond range, providing insights into non-stationary thermal diffusion at the nanoscale.

  View details for DOI 10.1038/s41467-023-42666-9

  View details for PubMedID 37949867

  View details for PubMedCentralID PMC10638245

• A Comparative Study on Overall Efficiency of Two-Dimensional Wireless Power Transfer Systems Using Rotational and Directional Methods IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS Wang, H., Zhang, C., Yang, Y., Liang, H., Hui, S. 2022; 69 (1): 260-269

  View details for DOI 10.1109/TIE.2020.3048317

  View details for Web of Science ID 000704120200028

• A Wearable Metasurface for High Efficiency, Free-Positioning Omnidirectional Wireless Power Transfer. New journal of physics Wang, H., Chen, Y. S., Zhao, Y. 2021; 23 (12)

  Abstract

  We introduce a design principle of metasurfaces that can form any desired distribution of magnetic field for high-efficiency wireless power transfer centered at 200 kHz, which can be used to efficiently charge implanted medical devices. This metasurface can improve the power transfer efficiency for both single-user and multi-user cases by over tenfold compared to those without the metasurface. Our design enables a robust field distribution to the positions of the transmitting and receiving coils, as well as the geometric distortions of the metasurface itself, demonstrating feasibilities as a wearable device. With our design, the field distribution and subsequent power division among the multiple users can be readily controlled from equal distribution to any selective user(s). When incorporating a three-dimensional unit cell of the metasurface, we theoretically demonstrate an omnidirectional control of the field orientation to achieve a high-efficiency wireless power transfer for multiple users.

  View details for DOI 10.1088/1367-2630/ac304a

  View details for PubMedID 34992495

  View details for PubMedCentralID PMC8725792

• Robust 3-D Wireless Power Transfer System Based on Rotating Fields for Multi-User Charging IEEE TRANSACTIONS ON ENERGY CONVERSION Wang, N., Wang, H., Mei, J., Mohammadi, S., Moon, J., Lang, J. H., Kirtley, J. L. 2021; 36 (2): 693-702

  View details for DOI 10.1109/TEC.2020.3034794

  View details for Web of Science ID 000652806800012

• On-demand field shaping for enhanced magnetic resonance imaging using an ultrathin reconfigurable metasurface VIEW Wang, H., Huang, H., Chen, Y., Zhao, Y. 2021; 2 (3)

  View details for DOI 10.1002/VIW.20200099

  View details for Web of Science ID 000664139900008

• Analysis and Performance Enhancement of Wireless Power Transfer Systems With Intended Metallic Objects IEEE TRANSACTIONS ON POWER ELECTRONICS Liang, H., Wang, H., Lee, C., Hui, S. 2021; 36 (2): 1388-1398

  View details for DOI 10.1109/TPEL.2020.3011761

  View details for Web of Science ID 000574748200023

• Ultra-high-frequency radio-frequency acoustic molecular imaging with saline nanodroplets in living subjects. Nature nanotechnology Chen, Y. S., Zhao, Y. n., Beinat, C. n., Zlitni, A. n., Hsu, E. C., Chen, D. H., Achterberg, F. n., Wang, H. n., Stoyanova, T. n., Dionne, J. n., Gambhir, S. S. 2021

  Abstract

  Molecular imaging is a crucial technique in clinical diagnostics but it relies on radioactive tracers or strong magnetic fields that are unsuitable for many patients, particularly infants and pregnant women. Ultra-high-frequency radio-frequency acoustic (UHF-RF-acoustic) imaging using non-ionizing RF pulses allows deep-tissue imaging with sub-millimetre spatial resolution. However, lack of biocompatible and targetable contrast agents has prevented the successful in vivo application of UHF-RF-acoustic imaging. Here we report our development of targetable nanodroplets for UHF-RF-acoustic molecular imaging of cancers. We synthesize all-liquid nanodroplets containing hypertonic saline that are stable for at least 2 weeks and can produce high-intensity UHF-RF-acoustic signals. Compared with concentration-matched iron oxide nanoparticles, our nanodroplets produce at least 1,600 times higher UHF-RF-acoustic signals at the same imaging depth. We demonstrate in vivo imaging using the targeted nanodroplets in a prostate cancer xenograft mouse model expressing gastrin release protein receptor (GRPR), and show that targeting specificity is increased by more than 2-fold compared with untargeted nanodroplets or prostate cancer cells not expressing this receptor.

  View details for DOI 10.1038/s41565-021-00869-5

  View details for PubMedID 33782588

• Optical force microscopy: combining light with atomic force microscopy for nanomaterial identification NANOPHOTONICS Jahan, N., Wang, H., Zhao, S., Dutta, A., Huang, H., Zhao, Y., Chen, Y. 2019; 8 (10): 1659-1671

  View details for DOI 10.1515/nanoph-2019-0181

  View details for Web of Science ID 000488235500005