• Application of atomic force microscope in diagnosis of single cancer cells

      Lu, Zhengcheng; Wang, Zuobin; Li, Dayou; ; University of Bedfordshire; Changchun University of Science and Technology (American Institute of Physics Inc., 2020-09-04)
      Changes in mechanical properties of cells are closely related to a variety of diseases. As an advanced technology on the micro/nano scale, atomic force microscopy is the most suitable tool for information acquisition of living cells in human body fluids. AFMs are able to measure and characterize the mechanical properties of cells which can be used as effective markers to distinguish between different cell types and cells in different states (benign or cancerous). Therefore, they can be employed to obtain additional information to that obtained via the traditional biochemistry methods for better identifying and diagnosing cancer cells for humans, proposing better treatment methods and prognosis, and unravelling the pathogenesis of the disease. In this report, we review the use of AFMs in cancerous tissues, organs, and cancer cells cultured in vitro to obtain cellular mechanical properties, demonstrate and summarize the results of AFMs in cancer biology, and look forward to possible future applications and the direction of development.
    • Effects of laser fluence on silicon modification by four-beam laser interference

      Zhao, Le; Wang, Zuobin; Zhang, Jinjin; Yu, Miao; Li, Siwei; Li, Dayou; Yue, Yong; Changchun University of Science and Technology; University of Bedfordshire; Jiaotong-Liverpool University (American Institute of Physics Inc., 2015-12-17)
      This paper discusses the effects of laser fluence on silicon modification by four-beam laser interference. In this work, four-beam laser interference was used to pattern single crystal silicon wafers for the fabrication of surface structures, and the number of laser pulses was applied to the process in air. By controlling the parameters of laser irradiation, different shapes of silicon structures were fabricated. The results were obtained with the single laser fluence of 354 mJ/cm, 495 mJ/cm, and 637 mJ/cm, the pulse repetition rate of 10 Hz, the laser exposure pulses of 30, 100, and 300, the laser wavelength of 1064 nm, and the pulse duration of 7-9 ns. The effects of the heat transfer and the radiation of laser interference plasma on silicon wafer surfaces were investigated. The equations of heat flow and radiation effects of laser plasma of interfering patterns in a four-beam laser interference distribution were proposed to describe their impacts on silicon wafer surfaces. The experimental results have shown that the laser fluence has to be properly selected for the fabrication of well-defined surface structures in a four-beam laser interference process. Laser interference patterns can directly fabricate different shape structures for their corresponding applications.
    • Fabrication of moth-eye structures on silicon by direct six-beam laser interference lithography

      Xu, Jia; Wang, Zuobin; Zhang, Ziang; Wang, Dapeng; Weng, Zhankun; Changchun University of Science and Technology; University of Bedfordshire (American Institute of Physics Inc., 2014-05-22)
      This paper presents a new method for the generation of cross-scale laser interference patterns and the fabrication of moth-eye structures on silicon. In the method, moth-eye structures were produced on a surface of silicon wafer using direct six-beam laser interference lithography to improve the antireflection performance of the material surface. The periodic dot arrays of the moth-eye structures were formed due to the ablation of the irradiance distribution of interference patterns on the wafer surface. The shape, size, and distribution of the moth-eye structures can be adjusted by controlling the wavelength, incidence angles, and exposure doses in a direct six-beam laser interference lithography setup. The theoretical and experimental results have shown that direct six-beam laser interference lithography can provide a way to fabricate cross-scale moth-eye structures for antireflection applications. © 2014 AIP Publishing LLC.
    • Fabrication of Pt nanowires with a diffraction-unlimited feature size by high-threshold lithography

      Li, Li; Wang, Zuobin; Li, Wenjun; Peng, Kuiqing; Zhang, Ziang; Yu, Miao; Song, Zhengxun; Weng, Zhankun; Wang, Dapeng; Zhao, Le; et al. (American Institute of Physics Inc., 2015-09-29)
      Although the nanoscale world can already be observed at a diffraction-unlimited resolution using far-field optical microscopy, to make the step from microscopy to lithography still requires a suitable photoresist material system. In this letter, we consider the threshold to be a region with a width characterized by the extreme feature size obtained using a Gaussian beam spot. By narrowing such a region through improvement of the threshold sensitization to intensity in a high-threshold material system, the minimal feature size becomes smaller. By using platinum as the negative photoresist, we demonstrate that high-threshold lithography can be used to fabricate nanowire arrays with a scalable resolution along the axial direction of the linewidth from the micro- to the nanoscale using a nanosecond-pulsed laser source with a wavelength λ0 = 1064 nm. The minimal feature size is only several nanometers (sub λ0/100). Compared with conventional polymer resist lithography, the advantages of high-threshold lithography are sharper pinpoints of laser intensity triggering the threshold response and also higher robustness allowing for large area exposure by a less-expensive nanosecond-pulsed laser.