• Controllable superhydrophobic surfaces with tunable adhesion fabricated by laser interference lithography

      Dong, Litong; Zhang, Ziang; Ding, Ran; Wang, Lu; Liu, Mengnan; Weng, Zhankun; Wang, Zuobin; Li, Dayou; Changchun University of Science and Technology; Changchun Observatory; et al. (Elsevier, 2019-05-15)
      Superhydrophobic surfaces with tunable wettability have attracted much attention in recent years, and many techniques have been developed to fabricate artificial function structures. However, applications of tunable adhesive superhydrophobic surfaces have been limited due to ambiguous structural factors on wettability. In thispaper, we studied the relationship between the surface adhesion and geometry parameters of periodic submicron structures, and presented a facile approach for the fabrication of controllable superhydrophobic surfaces with tunable adhesion through laser interference lithography (LIL) combined with inductively coupled plasma (ICP) etching. The wettability properties of periodic geometry structures were selected by tailoring the top area ratio of the pillar array. The findings of this work will contribute to quantifying structural parameters on the submicron scale through the combination of three-beam LIL and ICP etching for designing and developing new systems for micro-droplet manipulation. This approach can find potential applications in many fields such as targeted drug delivery, biomolecular quantitative detection, selective liquid transportation and oil/water separation.
    • Design an asymmetrical three-beam laser interference lithography for fabricating micro- and nano-structures

      Dong, Litong; Zhang, Ziang; Wang, Zuobin; Li, Dayou; Liu, Mengnan; Changchun University of Science and Technology; University of Bedfordshire; Changchun Observatory (Japan Laser Processing Society, 2020-09-01)
      Multi-beam laser interference lithography (LIL) has become one of the most important techniques and shown significant advantages in the fabrication of micro- and nano-structures. Controlling inten-sity ratio of optical distributions is a key issue in LIL for fabricating micro- and nano-structures. This paper presents an asymmetrical three-beam LIL system which effectively improves the intensity ratio of optical distributions. Comparing with the symmetrical three-beam interference, the asymmetrical three-beam LIL achieved the high intensity ratio of optical distribution when producing the similar interference pattern. In addition, this system also avoids modulation patterns in multi-beam LIL sys-tems and reduces the difficulty of actual LIL processing. A fast Fourier Transform (FFT) analysis used to study the pattern distributions of the asymmetrical three-beam interference from frequency spectra which shows that the pattern with a high-intensity array can be obtained by adjusting the parameter settings of incident laser beams. The asymmetrical three-beam LIL system was verified through fab-ricating patterns. The experimental results are in good agreement with the theoretical analyses.
    • Micro and nano dual-scale structures fabricated by amplitude modulation in multi-beam laser interference lithography

      Zhang, Ziang; Dong, Litong; Ding, Yunfeng; Li, Li; Weng, Zhankun; Wang, Zuobin; Changchun University of Science and Technology; Changchun Observatory (Optical Society of America, 2017-11-08)
      In this work, an effective method was presented to obtain a specific micro and nano dual-structures by amplitude modulation in multi-beam laser interference lithography (LIL). Moiré effect was applied to generate the amplitude modulation. The specific intensity modulation patterns can be obtained by the control of the parameter settings of incident laser beams. Both the incident angle and azimuth angle asymmetric configurations can cause the amplitude modulation in the interference optic field and the modulation period is determined by the angle offset. A four-beam LIL system was set up to fabricate patterns on photoresist and verify the method. The experimental results are in good agreement with the theoretical analysis.