[1] Isaac M and van Vuuren D P 2009 Modeling global residential sector energy demand for heating and air conditioning in the context of climate change Energy Policy 37 507-21

[2] Nakamura C, Yamamoto T, Manabe K, Nakamura T, Einaga Y and Shiratori S 2019 Thermoresponsive, freezing-resistant smart windows with adjustable transition temperature made from hydroxypropyl cellulose and glycerol Ind. Eng. Chem. Res. 58 6424-8

[3] Aburas M, Soebarto V, Williamson T, Liang R Q, Ebendorff-Heidepriem H and Wu Y P 2019 Thermochromic smart window technologies for building application: a review Appl. Energy 255 113522

[4] Li X H, Liu C, Feng S P and Fang N X 2019 Broadband light management with thermochromic hydrogel microparticles for smart windows Joule 3 290-302

[5] Wang Z L, Zhang Z M, Quan X J and Cheng P 2018 A numerical study on effects of surrounding medium, material, and geometry of nanoparticles on solar absorption efficiencies Int. J. Heat Mass Transfer 116 825-32

[6] Wang Z L, Yang P Y, Qi G G, Zhang Z M and Cheng P 2020 An experimental study of a nearly perfect absorber made from a natural hyperbolic material for harvesting solar energy J. Appl. Phys. 127 233102

[7] Zhou Y, Wang S C, Peng J Q, Tan Y T, Li C C, Boey F Y C and Long Y 2020 Liquid thermo-responsive smart window derived from hydrogel Joule 4 2458-74

[8] Wang S, Xu Z Q, Wang T T, Xiao T X, Hu X Y, Shen Y Z and Wang L Y 2018 Warm/cool-tone switchable thermochromic material for smart windows by orthogonally integrating properties of pillar[]arene and ferrocene Nat. Commun. 9 1737

[9] Ke Y J, Chen J W, Lin G J, Wang S C, Zhou Y, Yin J, Lee P S and Long Y 2019 Smart windows: electro-, thermo-, mechano-, photochromics, and beyond Adv. Energy Mater. 9 1902066

[10] Kim H N and Yang S 2020 Responsive smart windows from nanoparticle-polymer composites Adv. Funct. Mater. 30 1902597

[11] Ke Y J, Zhou C Z, Zhou Y, Wang S C, Chan S H and Long Y 2018 Emerging thermal-responsive materials and integrated techniques targeting the energy-efficient smart window application Adv. Funct. Mater. 28 1800113

[12] Mlyuka N R, Niklasson G A and Granqvist C G 2009 Thermochromic multilayer films of VO2 and TiO2 with enhanced transmittance Sol. Energy Mater. Sol. Cells 93 1685-7

[13] Chen Z, Gao Y F, Kang L T, Du J, Zhang Z T, Luo H J, Miao H Y and Tan G Q 2011 VO2-based double-layered films for smart windows: optical design, all-solution preparation and improved properties Sol. Energy Mater. Sol. Cells 95 2677-84

[14] Shen N, Chen S, Chen Z, Liu X L, Cao C X, Dong B R, Luo H J, Liu J J and Gao Y F 2014 The synthesis and performance of Zr-doped and W-Zr-codoped VO2 nanoparticles and derived flexible foils J. Mater. Chem. A 2 15087-93

[15] Zhou J D, Gao Y F, Liu X L, Chen Z, Dai L, Cao C X, Luo H J, Kanahira M, Sun C and Yan L M 2013 Mg-doped VO2 nanoparticles: hydrothermal synthesis, enhanced visible transmittance and decreased metal-insulator transition temperature Phys. Chem. Chem. Phys. 15 7505-11

[16] Zhou Y, Dong X X, Mi Y Y, Fan F, Xu Q, Zhao H, Wang S C and Long Y 2020 Hydrogel smart windows J. Mater. Chem. A 8 10007-25

[17] Han D, Lu Z C, Chester S A and Lee H 2018 Micro 3D printing of a temperature-responsive hydrogel using projection micro-stereolithography Sci. Rep. 8 1963

[18] Tang L, Wang L, Yang X, Feng Y Y, Li Y and Feng W 2021 Poly(N-isopropylacrylamide)-based smart hydrogels: design, properties and applications Prog. Mater. Sci. 115 100702

[19] Wang L Q, Liu F R, Qian J, Wu Z L and Xiao R 2021 Multi-responsive PNIPAM-PEGDA hydrogel composite Soft Matter 17 10421-7

[20] Zhu H and Wang L Y 2019 Smart window based on Cu7S4/hydrogel composites with fast photothermal response Sol. Energy Mater. Sol. Cells 202 110109

[21] Wu M C, Shi Y, Li R Y and Wang P 2018 Spectrally selective smart window with high near-infrared light shielding and controllable visible light transmittance ACS Appl. Mater. Interfaces 10 39819-27

[22] Zhou Y, Layani M, Wang S C, Hu P, Ke Y J, Magdassi S and Long Y 2018 Fully printed flexible smart hybrid hydrogels Adv. Funct. Mater. 28 1705365

[23] Yin Q, Guo Q, Wang Z L, Chen Y Q, Duan H G and Cheng P 2021 3D-printed bioinspired Cassie-baxter wettability for controllable microdroplet manipulation ACS Appl. Mater. Interfaces 13 1979-87

[24] Liao Y B, Li W H, Zhan Z H, Duan H G, Liu P, Chen Y Q and Wang Z L 2021 3D-printed complex microstructures with a self-sacrificial structure enabled by grayscale polymerization and ultrasonic treatment ACS Omega 6 18281-8

[25] Odent J, Wallin T J, Pan W Y, Kruemplestaedter K, Shepherd R F and Giannelis E P 2017 Highly elastic, transparent, and conductive 3D-printed ionic composite hydrogels Adv. Funct. Mater. 27 1701807

[26] Hong S, Sycks D, Chan H F, Lin S T, Lopez G P, Guilak F, Leong K W and Zhao X H 2015 3D printing of highly stretchable and tough hydrogels into complex, cellularized structures Adv. Mater. 27 4035-40

[27] Kunwar P, Jannini A V S, Xiong Z, Ransbottom M J, Perkins J S, Henderson J H, Hasenwinkel J M and Soman P 2020 High-resolution 3D printing of stretchable hydrogel structures using optical projection lithography ACS Appl. Mater. Interfaces 12 1640-9

[28] Li J H, Wu C T, Chu P K and Gelinsky M 2020 3D printing of hydrogels: rational design strategies and emerging biomedical applications Mater. Sci. Eng. R 140 100543

[29] Ge Q et al 2021 3D printing of highly stretchable hydrogel with diverse UV curable polymers Sci. Adv. 7 eaba4261

[30] Zhang B et al 2018 Highly stretchable hydrogels for UV curing based high-resolution multimaterial 3D printing J. Mater. Chem. B 6 3246-53

[31] Wang Z L, Chen L, Chen Y Q, Liu P, Duan H G and Cheng P 2020 3D printed ultrastretchable, hyper-antifreezing conductive hydrogel for sensitive motion and electrophysiological signal monitoring Research 2020 1426078

[32] Chen L, Wang Z L, Zhan Z H, Xie M Z, Duan G H, Cheng P, Chen Y Q and Duan H G 2021 3D printed super-anti-freezing self-adhesive human-machine interface Mater. Today Phys. 19 100404

[33] Darabi M A, Khosrozadeh A, Mbeleck R, Liu Y Q, Chang Q, Jiang J Z, Cai J, Wang Q, Luo G X and Xing M 2017 Skin-inspired multifunctional autonomic-intrinsic conductive self-healing hydrogels with pressure sensitivity, stretchability, and 3D printability Adv. Mater. 29 1700533

[34] Kye H, Koh Y G, Kim Y, Han S G, Lee H and Lee W 2017 Tunable temperature response of a thermochromic photonic gel sensor containing N-isopropylacrylamide and 4-acryloyilmorpholine Sensors 17 1398

[35] Ge Q, Li Z Q, Wang Z L, Kowsari K, Zhang W, He X N, Zhou J L and Fang N X 2020 Projection micro stereolithography based 3D printing and its applications Int. J. Extreme Manuf. 2 022004

[36] Zhou Y, Cai Y F, Hu X and Long Y 2015 VO2/hydrogel hybrid nanothermochromic material with ultra-high solar modulation and luminous transmission J. Mater. Chem. A 3 1121-6

[37] Yang Y S, Zhou Y, Yin Chiang F B and Long Y 2016 Temperature-responsive hydroxypropylcellulose based thermochromic material and its smart window application RSC Adv. 6 61449-53

[38] Lee H Y, Cai Y F, Velioglu S, Mu C Z, Chang C J, Chen Y L, Song Y J, Chew J W and Hu X M 2017 Thermochromic Ionogel: a new class of stimuli responsive materials with super cyclic stability for solar modulation Chem. Mater. 29 6947-55

[39] Wei G Y, Yang D Y, Zhang T, Yue X J and Qiu F X 2020 Thermal-responsive PNIPAm-acrylic/Ag NRs hybrid hydrogel with atmospheric window full-wavelength thermal management for smart windows Sol. Energy Mater. Sol. Cells 206 110336

[40] Aden A L and Kerker M 1951 Scattering of electromagnetic waves from two concentric spheres J. Appl. Phys. 22 1242-6

[41] Wang Z L, Quan X J, Zhang Z M and Cheng P 2018 Optical absorption of carbon-gold core-shell nanoparticles J. Quant. Spectrosc. Radiat. Transfer 205 291-8

[42] Wang Z L and Cheng P 2019 Enhancements of absorption and photothermal conversion of solar energy enabled by surface plasmon resonances in nanoparticles and metamaterials Int. J. Heat Mass Transfer 140 453-82

[43] Wang Z L, Zhang Z M, Quan X J and Cheng P 2018 A perfect absorber design using a natural hyperbolic material for harvesting solar energy Sol. Energy 159 329-36

[44] Liang Q Q, Yin Q, Chen L, Wang Z L and Chen X D 2020 Perfect spectrally selective solar absorber with dielectric filled fishnet tungsten grating for solar energy harvesting Sol. Energy Mater. Sol. Cells 215 110664

[45] ASTM G159-98 1998 Standard tables for references solar spectral irradiance at air mass 1.5: direct normal and hemispherical for a 37° tilted surface (Withdrawn 2005) (West Conshohocken, PA: ASTM International)