Superior improvement in dynamic response of liquid crystal lens using organic and inorganic nanocomposite

Che Ju Hsu; Bhupendra Pratap Singh; Pravinraj Selvaraj; Mareena Antony; Rajiv Manohar; Chi Yen Huang

doi:10.1038/s41598-021-96991-4

Superior improvement in dynamic response of liquid crystal lens using organic and inorganic nanocomposite

Sci Rep. 2021 Aug 30;11(1):17349. doi: 10.1038/s41598-021-96991-4.

Authors

Che Ju Hsu¹, Bhupendra Pratap Singh², Pravinraj Selvaraj³, Mareena Antony³, Rajiv Manohar², Chi Yen Huang⁴

Affiliations

¹ Graduate Institute of Photonics, National Changhua University of Education, Changhua, 500, Taiwan.
² Liquid Crystal Research Lab, Physics Department, University of Lucknow, Lucknow, 226007, India.
³ Department of Physics, National Changhua University of Education, Changhua, 500, Taiwan.
⁴ Graduate Institute of Photonics, National Changhua University of Education, Changhua, 500, Taiwan. chiyen@cc.ncue.edu.tw.

Abstract

In this study, the response time of a 4 mm-aperture hole-patterned liquid crystal (HLC) lens has been significantly improved with doping of N-benzyl-2-methyl-4-nitroaniline (BNA) and rutile titanium dioxide nanoparticle (TiO₂ NP) nanocomposite. The proposed HLC lens provides the focus and defocus times that are 8.5× and 14× faster than the pristine HLC lens, respectively. Meanwhile, the focus and defocus times of the proposed HLC lens reach the order of millisecond. Result shows that the synergistic effect of BNA and TiO₂ NP induces a 78% decrement in the viscosity of pristine LC mixture that significantly shortens the focus and defocus times of HLC lens. The remarkable decrement in viscosity is mainly attributed to spontaneous polarization electric fields from the permanent dipole moments of the additives. Besides, the strengthened electric field surrounding TiO₂ NP assists in decreasing the focus time of HLC lens. The focus and defocus times of HLC lens are related to the wavefront (or phase profile) bending speed. The time-dependent phase profiles of the HLC lenses with various viscosities are calculated. This result shows the decrease in wavefront bending time is not simply proportional to viscosity decrement. Furthermore, the proposed HLC lens emerges a larger tunable focus capability within smaller voltage interval than the pristine HLC lens.

Abstract

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