[1] Xia Y, Whitesides GM. Soft lithography. Annu Rev Mater Sci. 1998;28:153–184.

[2] Singh M, Haverinen HM, Dhagat P, Jabbour GE. Inkjet printing-process and its applications. Adv Mater. 2010;22(6):673–685.

[3] del Pozo M, Sol JAHP, Schenning APHJ, Debije MG. 4D printing of liquid crystals: What’s right for me? Adv Mater. 2022;34(3):e2104390.

[4] Mkhize N, Bhaskaran H. Electrohydrodynamic jet printing: Introductory concepts and considerations. Small Sci. 2022;2(2):2100073.

[5] Reizabal A, Tandon B, Lanceros-Méndez S, Dalton PD. Electrohydrodynamic 3D printing of aqueous solutions. Small. 2023;19(7): Article e2205255.

[6] Jandyal A, Chaturvedi I, Wazir I, Raina A, Ul Haq MI. 3D printing—A review of processes, materials and applications in industry 4.0. Sustain Oper Comput. 2022;3:33–42.

[7] Saadi MASR, Maguire A, Pottackal NT, Thakur MSH, Ikram MM, Hart AJ, Ajayan PM, Rahman MM. Direct ink writing: A 3D printing technology for diverse materials. Adv Mater. 2022;34(28): Article e2108855.

[8] Liu Z, Li M, Dong X, Ren Z, Hu W, Sitti M. Creating three-dimensional magnetic functional microdevices via molding-integrated direct laser writing. Nat Commun. 2022;13(1):2016.

[9] Sedghamiz E, Liu M, Wenzel W. Challenges and limits of mechanical stability in 3D direct laser writing. Nat Commun. 2022;13(1):2115.

[10] del Pozo M, Delaney C, Pilz da Cunha M, Debije MG, Florea L, Schenning APHJ. Temperature-responsive 4D liquid crystal microactuators fabricated by direct laser writing by two-photon polymerization. Small Struct. 2022;3(2):2100158.

[11] Rao DGS, Palacharla V, Swarnakar S, Kumar S. Design of all-optical D flip-flop using photonic crystal waveguides for optical computing and networking. Appl Optics. 2020;59(23):7139–7143.

[12] Wang X, Xie P, Chen B, Zhang X. Chip-based high-dimensional optical neural network. Nano-Micro Lett. 2022;14(1):221.

[13] Liu Y, Wang P, Wang Y, Lin Z, Liu H, Huang J, Huang Y, Duan X. van der Waals integrated devices based on nanomembranes of 3D materials. Nano Lett. 2020;20(2):1410–1416.

[14] Ni Y, Chen C, Wen S, Xue X, Sun L, Yang Y. Computational spectropolarimetry with a tunable liquid crystal metasurface. eLight. 2022;2:23.

[15] Meng Y, Chen Y, Lu L, Ding Y, Cusano A, Fan JA, Hu Q, Wang K, Xie Z, Liu Z, et al. Optical meta-waveguides for integrated photonics and beyond. Light Sci Appl. 2021;10(1):235.

[16] Huang Y, Xu Y, Bisoyi HK, Liu Z, Wang J, Tao Y, Yang T, Huang S, Yang H, Li Q. Photocontrollable elongation actuation of liquid crystal elastomer films with well-defined crease structures. Adv Mater. 2023;35(36): Article e2304378.

[17] Ma L-L, Li CY, Pan JT, Ji YE, Jiang C, Zheng R, Wang ZY, Wang Y, Li BX, Lu YQ. Self-assembled liquid crystal architectures for soft matter photonics. Light Sci Appl. 2022;11(1):270.

[18] Chen J, Xiong Y, Xu F, Lu Y. Silica optical fiber integrated with two-dimensional materials: Towards opto-electro-mechanical technology. Light Sci Appl. 2021;10(1):78.

[19] Zhou S, Shen Z, Li X, Ge S, Lu Y, Hu W. Liquid crystal integrated metalens with dynamic focusing property. Opt Lett. 2020;45(15):4324–4327.

[20] Zhu S, Chen X, Liu X, Zhang G, Tian P. Recent progress in and perspectives of underwater wireless optical communication. Prog Quantum Electron. 2020;73: Article 100274.

[21] He J, Dong T, Xu Y. Review of photonic integrated optical phased arrays for space optical communication. IEEE Access. 2020;8:188284–188298.

[22] Zhu Z, Janasik M, Fyffe A, Hay D, Zhou Y, Kantor B, Winder T, Boyd RW, Leuchs G, Shi Z. Compensation-free high-dimensional free-space optical communication using turbulence-resilient vector beams. Nat Commun. 2021;12(1):1666.

[23] Yu B-Y, Yue DW, Hou KX, Ju L, Chen H, Ding C, Liu ZG, Dai YQ, Bisoyi HK, Guan YS, et al. Stretchable and self-healable spoof plasmonic meta-waveguide for wearable wireless communication system. Light Sci Appl. 2022;11(1):307.

[24] Zola RS, Bisoyi HK, Wang H, Urbas AM, Bunning TJ, Li Q. Dynamic control of light direction enabled by stimuli-responsive liquid crystal gratings. Adv Mater. 2019;31: Article e1806172.

[25] Xiong J, Wu S-T. Planar liquid crystal polarization optics for augmented reality and virtual reality: From fundamentals to applications. eLight. 2021;1:3.

[26] Jisha CP, Arumugam SV, Marrucci L, Nolte S, Alberucci A. Waveguiding driven by the Pancharatnam-Berry phase. Phys Rev A. 2023;107: Article 013523.

[27] Wei T, Chen P, Tang MJ, Wu GX, Chen ZX, Shen ZX, Ge SJ, Xu F, Hu W, Lu YQ. Liquid-crystal-mediated active waveguides toward programmable integrated optics. Adv Opt Mater. 2020;8(10):1902033.

[28] Chen S, Zhuo M-P, Wang X-D, Wei G-Q, Liao L-S. Optical waveguides based on one-dimensional organic crystals. PhotoniX. 2021;2:2.

[29] Annadhasan M, Basak S, Chandrasekhar N, Chandrasekar R. Next-generation organic photonics: The emergence of flexible crystal optical waveguides. Adv Opt Mater. 2020;8(21):2000959.

[30] Tian D, Chen Y. Optical waveguides in organic crystals of polycyclic arenes. Adv Opt Mater. 2021;9(23):2002264.

[31] Wu S, Zhou B, Yan D. Recent advances on molecular crystalline luminescent materials for optical waveguides. Adv Opt Mater. 2021;9(23):2001768.

[32] Hsiang E-L, Wu S-T. Novel developments in computational spectropolarimeter. Light Sci Appl. 2023;12(1):52.

[33] Jain P, Honnungar RV. A review on materials for integrated optical waveguides. Paper presented at: Proceedings of Fourth International Conference on Inventive Material Science Applications. Advances in Sustainability Science and Technology; 2021 Oct. 20; Springer Singapore.

[34] Chakravarty S, Teng M, Safian R, Zhuang L. Hybrid material integration in silicon photonic integrated circuits. J Semicond. 2021;42: Article 041303.

[35] Ding Y, Li Y, Yang Q, Wu S. Design optimization of polarization volume gratings for full-color waveguide-based augmented reality displays. J Soc Inf Disp. 2023;31(5):380–386.

[36] Chen X, Li C, Tsang HK. Device engineering for silicon photonics. NPG Asia Mater. 2011;3:34–40.

[37] Bogaerts W, Chrostowski L. Silicon photonics circuit design: Methods, tools and challenges. Laser Photon Rev. 2018;12(4):1700237.

[38] Zheng R, Ma L, Feng W, Pan J, Wang Z, Chen Z, Zhang Y, Li C, Chen P, Bisoyi HK, et al. Autonomous self-sustained liquid crystal actuators enabling active photonic applications. Adv Funct Mater. 2023;33(38):2301142.

[39] Bisoyi HK, Li Q. Liquid crystals: Versatile self-organized smart soft materials. Chem. Rev. 2022;122(5):4887–4926.

[40] Yin K, Hsiang EL, Zou J, Li Y, Yang Z, Yang Q, Lai PC, Lin CL, Wu ST. Advanced liquid crystal devices for augmented reality and virtual reality displays: Principles and applications. Light Sci Appl. 2022;11(1):161.

[41] Xiong J, Yang Q, Li Y, Wu S-T. Holo-imprinting polarization optics with a reflective liquid crystal hologram template. Light Sci Appl. 2022;11(1):54.

[42] Zhang X, Xu Y, Valenzuela C, Zhang X, Wang L, Feng W, Li Q. Liquid crystal-templated chiral nanomaterials: From chiral plasmonics to circularly polarized luminescence. Light Sci Appl. 2022;11(1):223.

[43] Coles H, Morris S. Liquid-crystal lasers. Nat Photonics. 2010;4:676–685.

[44] Chen X-M, Feng WJ, Bisoyi HK, Zhang S, Chen X, Yang H, Li Q. Light-activated photodeformable supramolecular dissipative self-assemblies. Nat Commun. 2022;13:3216.

[45] Wei B, Zhang Y, Li P, Liu S, Hu W, Lu Y, Wu Y, Dou X, Zhao J. Liquid-crystal splitter for generating and separating autofocusing and autodefocusing circular Airy beams. Opt Express. 2020;28(18):26151–26160.

[46] Li S, Bai H, Liu Z, Zhang X, Huang C, Wiesner LW, Silberstein M, Shepherd RF. Digital light processing of liquid crystal elastomers for self-sensing artificial muscles. Sci Adv. 2021;7(30): Article eabg3677.

[47] Wu J, Wu SB, Cao HM, Chen QM, Lu YQ, Hu W. Electrically tunable microlens array enabled by polymer-stabilized smectic hierarchical architectures. Adv Opt Mater. 2022;10(20):2201015.

[48] Bolis S, Gorza SP, Elston SJ, Neyts K, Kockaert P, Beeckman J. Spatial fluctuations of optical solitons due to long-range correlated dielectric perturbations in liquid crystals. Phys Rev A. 2017;96: Article 031803.

[49] Du F, Lu Y-Q, Wu S-T. Electrically tunable liquid-crystal photonic crystal fiber. Appl Phys Lett. 2004;85:2181–2183.

[50] Chen P, Wei B, Hu W, Lu Y. Liquid-crystal-mediated geometric phase: From transmissive to broadband reflective planar optics. Adv Mater. 2020;32(27): Article e1903665.

[51] Zografopoulos DC, Asquini R, Kriezis EE, D’Alessandro A, Beccherelli R. Guided-wave liquid-crystal photonics. Lab Chip. 2012;12(19):3598.

[52] Lammers K, Alberucci A, Pannian J, Szameit A, Nolte S. Hybridization of femtosecond-laser written waveguides with liquid crystals. Optica Open. Preprint. 2023.

[53] Rüetschi M, Grütter P, Fünfschilling J, Güntherodt H-J. Creation of liquid crystal waveguides with scanning force microscopy. Science. 1994;265(5171):512–514.

[54] Whinnery J, Chenming H, Kwon Y. Liquid-crystal waveguides for integrated optics. IEEE J Quantum Electron. 1977;13(4):262–267.

[55] Hu C, Whinnery JR. Losses of a nematic liquid-crystal optical waveguide*. J Opt Soc Am. 1974;64(11):1424–1432.

[56] Asquini R, Fratalocchi A, D’Alessandro A, Assanto G. Electro-optic routing in a nematic liquid-crystal waveguide. Appl Optics. 2005;44(19):4136–4143.

[57] Park H-G, Barrelet CJ, Wu Y, Tian B, Qian F, Lieber CM. A wavelength-selective photonic-crystal waveguide coupled to a nanowire light source. Nat Photonics. 2008;2: 622–626.

[58] Fratalocchi A, Assanto G, Brzdąkiewicz KA, Karpierz MA. Optical multiband vector breathers in tunable waveguide arrays. Opt Lett. 2005;30(2):174–176.

[59] Kasano M, Ozaki M, Yoshino K, Ganzke D, Haase W. Electrically tunable waveguide laser based on ferroelectric liquid crystal. Appl Phys Lett. 2003;82:4026–4028.

[60] Presnyakov VV, Liu ZJ, Chigrinov VG. Infiltration of photonic crystal fiber with liquid crystals. Paper presented at: Proc. SPIE 6017, Nanophotonics for Communication: Materials and Devices II, 60170J; 2005; Boston, MA, USA.

[61] Beeckman J, James R, Fernandez FA, de Cort W, Vanbrabant PJM, Neyts K. Calculation of fully anisotropic liquid crystal waveguide modes. J Light Technol. 2009;27(17):3812–3819.

[62] Beeckman J. Liquid-crystal photonic applications. Opt Eng. 2011;50(8): Article 081202.

[63] Bogaerts W, Adamski A, Beeckman J, Neyts K, Baets R. Silicon-on-insulator optical waveguides with liquid crystal cladding for switching and tuning. Paper presented at: Proceedings of the European Conference on Optical Communications; 2003.

[64] De Cort W, Beeckman J, James R, Fernández FA, Baets R, Neyts K. Tuning of silicon-on-insulator ring resonators with liquid crystal cladding using the longitudinal field component. Opt Lett. 2009;34(13):2054.

[65] d’Alessandro A, Bellini B, Donisi D, Beccherelli R, Asquini R. Nematic liquid crystal optical channel waveguides on silicon. IEEE J Quantum Electron. 2006;42(10):1084–1090.

[66] Donisi D, Bellini B, Beccherelli R, Asquini R, Gilardi G, Trotta M, d’Alessandro A. A switchable liquid-crystal optical channel waveguide on silicon. IEEE J. Quantum Electron. 2010;46(5):762–768.

[67] Cai D-P, Nien S-C, Chiu H-K, Chen C-C, Lee C-C. Electrically tunable liquid crystal waveguide attenuators. Opt Express. 2011;19(12):11890.

[68] d’Alessandro A, Martini L, Civita L, Beccherelli R, Asquini R. Liquid crystal waveguide technologies for a new generation of low-power photonic integrated circuits. SPIE Proc. 2015;9384:74–81.

[69] Zhao H, O’Brien K, Li S, Shepherd RF. Optoelectronically innervated soft prosthetic hand via stretchable optical waveguides. Sci Robot. 2016;1(1): Article eaai7529.

[70] Wang A, Das A, Grojo D. Ultrafast laser writing deep inside silicon with THz-repetition-rate trains of pulses. Research. 2020;2020: Article 8149764.

[71] Kollipara PS, Li J, Zheng Y. Optical patterning of two-dimensional materials. Research. 2020;2020: Article 6581250.

[72] Lin Z, Hong M. Femtosecond laser precision engineering: From micron, submicron, to nanoscale. Ultrafast Sci. 2021;2021: Article 9783514.

[73] Chen B, Zhao Z, Morris SM. Chiral switches bring new twist to photonics. Nat Photonics. 2022;16:174–175.

[74] Li L, Lin H, Qiao S, Zou Y, Danto S, Richardson K, Musgraves JD, Lu N, Hu J. Integrated flexible chalcogenide glass photonic devices. Nat Photonics. 2014;8:643–649.

[75] Salari V, Rodrigues S, Saglamyurek E, Simon C, Oblak D. Are brain–computer interfaces feasible with integrated photonic chips? Front Neurosci. 2022;15:780344.

[76] Cabrera LY, Weber DJ. Rethinking the ethical priorities for brain–computer interfaces. Nat Electron. 2023;6:99–101.

[77] Ahmad Tarar A, Mohammad U, Srivastava SK. Wearable skin sensors and their challenges: A review of transdermal, optical, and mechanical sensors. Biosensors. 2020;10(6):56.

[78] Kuenstler AS, Kim H, Hayward RC. Liquid crystal elastomer waveguide actuators. Adv Mater. 2019;31(24): Article e1901216.

[79] Batula AM, Mark J, Kim YE, Ayaz H. Developing an optical brain-computer interface for humanoid robot control. In: Schmorrow D, Fidopiastis C, editors. Foundations of augmented cognition: Neuroergonomics and operational neuroscience. AC 2016. Lecture Notes in Computer Science. Cham: Springer; 2016.

[80] Chen B, Zhao Z, Nourshargh C, He C, Salter PS, Booth MJ, Elston SJ, Morris SM. Laser written stretchable diffractive optic elements in liquid crystal gels. Crystals. 2022;12(10):1340.

[81] Sandford O’Neill J. 3D switchable diffractive optical elements fabricated with two-photon polymerization. Adv Opt Mater. 2022;10(7):2102446.

[82] Szobota S, Isacoff EY. Optical control of neuronal activity. Annu Rev Biophys. 2010;39:329–348.

[83] Boyden ES, Zhang F, Bamberg E, Nagel G, Deisseroth K. Millisecond-timescale, genetically targeted optical control of neural activity. Nat Neurosci. 2005;8(9):1263–1268.

[84] Xiong H, Alberto KA, Youn J, Taura J, Morstein J, Li X, Wang Y, Trauner D, Slesinger PA, Nielsen SO, et al. Optical control of neuronal activities with photoswitchable nanovesicles. Nano Res. 2023;16(1):1033–1041.

[85] Ayaz H, Shewokis PA, Bunce S, Onaral B. An optical brain computer interface for environmental control. Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:6327–6330.

[86] Tang X, Shen H, Zhao S, Li N, Liu J. Flexible brain–computer interfaces. Nat Electron. 2023;6:109–118.