cholesteric lcd display free sample

To achieve broadband photonic elements, CLC paints are first prepared using an optimized composition for coating. A cRM with a photopolymerizable methacrylate group is a core component of the CLC paints, as shown in Fig. 1a. Due to the presence of an R-configured naphthyl group, simply adjusting the concentration of the cRM in the nematic liquid crystal (NLC) medium enables the formation of cholesteric mesophases. In this study, a monoacrylate monomer (mRM) and a diacrylate monomer (dRM) are purposely used not only as the NLC host but also as chemical crosslinkers1b). For the CLC paints obtained with the cRM and dRM, the growth of a needle-like texture is observed in the POM microphotographs after a few minutes (Figure S1 in the Supporting Information). However, the CLC paints with the mRM maintain their ordered structure without any phase separation, which results in their dramatically enhanced processability, even at the room temperature (Figure S2 in the Supporting Information). In the planar anchoring condition, the molecules lie down on the surface and the HA of self-assembled helical nanostructure is parallel to the surface normal. Therefore, the mRM and dRM mixtures doped with 12, 10, and 8 wt% cRM clearly exhibit the selective reflection of blue, green, and red light, respectively (insets in Fig. 1b).

CLC paints with unique optical properties and a suitable viscoelasticity can be used for various applications, such as architectural coatings, colorimetric sensors, and information displays2a, the pinky, ring, and middle fingers covered with the CLC films are red, green, and blue, respectively. The ability to localize the presence and color of the CLC paints is further described. The artificial nails on the thumb and index fingers illustrate prototypical symbols of the cholesteric character. When the CLC paints described above are cast on a glass substrate, a free-standing and circular-polarizing photonic material with macroscopic dimensions can be fabricated. The cast sample is evenly sheared with a bar coater. Then, the in situ photopolymerization of the coated sample is performed to obtain a robust optical film. The photoinitiated polymerization is induced by exposure to 365 nm UV light for 10 min. Based on a field adhesion method (ASTM D3359), the CLC films exhibit better mechanical properties than the CLC paints (Figure S3 in the Supporting Information)

Application of the chirophotonic crystal paints as fingernail polish (a). Macroscopic images of three free-standing CLC films illustrating the iridescence inherent to the cholesteric mesophase and the retention of the blue, green, and red reflection colors (b). Transmittance spectra indicating that the photopolymerized CLC paints reflect red, green, and blue (c). DMA thermograms of FB (d). Transformation of the CLC paints to films after UV polymerization (e)

The polymeric stabilization of the CLC paints can be easily handled with a tweezer (Fig. 2b). The thickness of the CLC films is controlled to 10 μm. The colors of the CLC films observed by the naked eye are nearly the same as those of the CLC paints. The proposed fully reactive cholesteric system is intentionally designed to minimize phase separation during photopolymerizationR), green (FG), and blue (FB) colors, respectively. The corresponding characteristic light reflections are λmax = 435, 525, and 630 nm, respectively (Fig. 2c). These results also indicate good dimensional stability. The nearly identical positions of the reflection notches of the CLC paints and films indicate that the P value is not affected by the photopolymerization (Figure S4 in the Supporting Information). The thermomechanical properties of the CLC films are examined by a dynamic mechanical analyzer (DMA). In the example at the top, the FB sample exhibits good flexibility. It has a glass transition temperature (Tg) of 85 °C (obtained from the peak value of the tan δ curve) and a storage modulus (E′) of 1.2 GPa at room temperature (Fig. 2d). The thermomechanical properties determined by DMA are in good agreement with those measured by DSC, which confirms that Tg = 85 °C (Figure S5 in the Supporting Information). Under these conditions, the conversion of the chiral and achiral RMs is calculated by monitoring the change in the transmittance area of the FTIR peak at 810 cm−1, which is the out-of-plane bending vibration peak of the acrylate group2e shows that the conversion is 81%.

After the copolymerization of the chiral and achiral RMs, the CLC films are stable to chemical attack. The chemical stability of the CLC paints is first tested by dropping various solvents on them. The helical nanostructures of the CLC paints are damaged by the attack of organic solvents. For example, the CLC paints are fully dissolved and completely lose their reflection colors when exposed to chloroform. The ordered structure is disrupted by the penetration of the solvent molecules. However, the CLC films can withstand common organic solvents, as shown by the summarized results in Figure S6 in the Supporting Information. Based on the chemical stability tests, it is concluded that the construction of the crosslinked helical nanostructure is an effective method for obtaining robust photonic materials. Furthermore, it should be noted that it is possible to fabricate a patterned optical object if a photomask is applied3a. The butterfly-shaped object is free-standing (Fig. 3b). Due to the properties of the cholesteric mesophase, it retains the blue reflection and the notch at approximately 435 nm when probed with right-handed (RH) circularly polarized light (CPL). However, left-handed (LH) CPL is transmitted, and no reflection color is observed (Fig. 3c)3d.

The mirror-like silver reflection of F3 is illustrated in Fig. 5a. A common illustration of the cholesteric mesophase is visible behind F3 (Fig. 5b). The microstructures of the CLC films are observed by 1D WAXD. A broad peak appears at approximately 2θ = 20.13°, indicating the existence of the cholesteric mesophase (Figure S9 in the Supporting Information). The peak at 0.44 nm originates from the liquid-like correlation of the anisotropic molecules. The strong birefringence and oily streaked texture detected by POM further support the successful transfer of the chiral property and helical information of the CLC paints to the corresponding films (Figure S10 in the Supporting Information). To visualize the distinct helical nanostructures within the broadband mirrors, SEM is employed. As shown in Fig. 5c, the cross-sectional SEM image of F3 has a 30 μm-thick layer (three stacked 10 μm layers of CLCs). The lengths of Pred = 420 nm, Pgreen = 350 nm, and Pblue = 290 nm are measured. The red, green, and blue layers of F3 have 24, 28, and 34 pitches, respectively. Note that only a single helical nanostructure constructed by the self-assembly of the CLC paints in the red, green, and blue layers of F3 is schematically illustrated in Fig. 5d.

To achieve broadband photonic elements, CLC paints are first prepared using an optimized composition for coating. A cRM with a photopolymerizable methacrylate group is a core component of the CLC paints, as shown in Fig. 1a. Due to the presence of an R-configured naphthyl group, simply adjusting the concentration of the cRM in the nematic liquid crystal (NLC) medium enables the formation of cholesteric mesophases. In this study, a monoacrylate monomer (mRM) and a diacrylate monomer (dRM) are purposely used not only as the NLC host but also as chemical crosslinkers1b). For the CLC paints obtained with the cRM and dRM, the growth of a needle-like texture is observed in the POM microphotographs after a few minutes (Figure S1 in the Supporting Information). However, the CLC paints with the mRM maintain their ordered structure without any phase separation, which results in their dramatically enhanced processability, even at the room temperature (Figure S2 in the Supporting Information). In the planar anchoring condition, the molecules lie down on the surface and the HA of self-assembled helical nanostructure is parallel to the surface normal. Therefore, the mRM and dRM mixtures doped with 12, 10, and 8 wt% cRM clearly exhibit the selective reflection of blue, green, and red light, respectively (insets in Fig. 1b).

CLC paints with unique optical properties and a suitable viscoelasticity can be used for various applications, such as architectural coatings, colorimetric sensors, and information displays2a, the pinky, ring, and middle fingers covered with the CLC films are red, green, and blue, respectively. The ability to localize the presence and color of the CLC paints is further described. The artificial nails on the thumb and index fingers illustrate prototypical symbols of the cholesteric character. When the CLC paints described above are cast on a glass substrate, a free-standing and circular-polarizing photonic material with macroscopic dimensions can be fabricated. The cast sample is evenly sheared with a bar coater. Then, the in situ photopolymerization of the coated sample is performed to obtain a robust optical film. The photoinitiated polymerization is induced by exposure to 365 nm UV light for 10 min. Based on a field adhesion method (ASTM D3359), the CLC films exhibit better mechanical properties than the CLC paints (Figure S3 in the Supporting Information)

Application of the chirophotonic crystal paints as fingernail polish (a). Macroscopic images of three free-standing CLC films illustrating the iridescence inherent to the cholesteric mesophase and the retention of the blue, green, and red reflection colors (b). Transmittance spectra indicating that the photopolymerized CLC paints reflect red, green, and blue (c). DMA thermograms of FB (d). Transformation of the CLC paints to films after UV polymerization (e)

The polymeric stabilization of the CLC paints can be easily handled with a tweezer (Fig. 2b). The thickness of the CLC films is controlled to 10 μm. The colors of the CLC films observed by the naked eye are nearly the same as those of the CLC paints. The proposed fully reactive cholesteric system is intentionally designed to minimize phase separation during photopolymerizationR), green (FG), and blue (FB) colors, respectively. The corresponding characteristic light reflections are λmax = 435, 525, and 630 nm, respectively (Fig. 2c). These results also indicate good dimensional stability. The nearly identical positions of the reflection notches of the CLC paints and films indicate that the P value is not affected by the photopolymerization (Figure S4 in the Supporting Information). The thermomechanical properties of the CLC films are examined by a dynamic mechanical analyzer (DMA). In the example at the top, the FB sample exhibits good flexibility. It has a glass transition temperature (Tg) of 85 °C (obtained from the peak value of the tan δ curve) and a storage modulus (E′) of 1.2 GPa at room temperature (Fig. 2d). The thermomechanical properties determined by DMA are in good agreement with those measured by DSC, which confirms that Tg = 85 °C (Figure S5 in the Supporting Information). Under these conditions, the conversion of the chiral and achiral RMs is calculated by monitoring the change in the transmittance area of the FTIR peak at 810 cm−1, which is the out-of-plane bending vibration peak of the acrylate group2e shows that the conversion is 81%.

After the copolymerization of the chiral and achiral RMs, the CLC films are stable to chemical attack. The chemical stability of the CLC paints is first tested by dropping various solvents on them. The helical nanostructures of the CLC paints are damaged by the attack of organic solvents. For example, the CLC paints are fully dissolved and completely lose their reflection colors when exposed to chloroform. The ordered structure is disrupted by the penetration of the solvent molecules. However, the CLC films can withstand common organic solvents, as shown by the summarized results in Figure S6 in the Supporting Information. Based on the chemical stability tests, it is concluded that the construction of the crosslinked helical nanostructure is an effective method for obtaining robust photonic materials. Furthermore, it should be noted that it is possible to fabricate a patterned optical object if a photomask is applied3a. The butterfly-shaped object is free-standing (Fig. 3b). Due to the properties of the cholesteric mesophase, it retains the blue reflection and the notch at approximately 435 nm when probed with right-handed (RH) circularly polarized light (CPL). However, left-handed (LH) CPL is transmitted, and no reflection color is observed (Fig. 3c)3d.

The mirror-like silver reflection of F3 is illustrated in Fig. 5a. A common illustration of the cholesteric mesophase is visible behind F3 (Fig. 5b). The microstructures of the CLC films are observed by 1D WAXD. A broad peak appears at approximately 2θ = 20.13°, indicating the existence of the cholesteric mesophase (Figure S9 in the Supporting Information). The peak at 0.44 nm originates from the liquid-like correlation of the anisotropic molecules. The strong birefringence and oily streaked texture detected by POM further support the successful transfer of the chiral property and helical information of the CLC paints to the corresponding films (Figure S10 in the Supporting Information). To visualize the distinct helical nanostructures within the broadband mirrors, SEM is employed. As shown in Fig. 5c, the cross-sectional SEM image of F3 has a 30 μm-thick layer (three stacked 10 μm layers of CLCs). The lengths of Pred = 420 nm, Pgreen = 350 nm, and Pblue = 290 nm are measured. The red, green, and blue layers of F3 have 24, 28, and 34 pitches, respectively. Note that only a single helical nanostructure constructed by the self-assembly of the CLC paints in the red, green, and blue layers of F3 is schematically illustrated in Fig. 5d.

A novel device for cholesteric liquid crystal (CLC)-based microfluidic chips, accommodated in a polydimethylsiloxane material, was invented. In this device, the reorientation of the CLCs was consistently influenced by the surface of the four channel walls and adjacent CLCs. When the inside of the microchannel was coated with the alignment layer, the CLCs oriented homeotropically in a focal conic state under cross-polarizers. Once antigens had bound onto antibodies immobilized onto the orientation sheet-coated channel walls, the light intensity of the CLC molecules converted from a focal conic state to a bright planar state caused by disrupting the CLCs. By means of utilizing pressure-propelling flow, the attachment of antigen/antibody to the CLCs should be detectable within consecutive sequences. The multi-microfluidic CLC-based chips were verified by measuring bovine serum albumin (BSA) and immune complexes of pairs of BSA antigen/antibody. We showed that the multiple microfluidic immunoassaying can be used for measuring BSA and pairs of antigen/antibody BSA with a detection limit of about 1 ng/mL. The linear range is 0.1 μg/mL–1 mg/mL. A limit of immune detection of pairs of BSA antigens/antibodies was 10 ng/mL of BSA plus 1000 ng/mL of the anti-BSA antibodies was observed. According to this innovative creation of immunoassaying, an unsophisticated multi-detection device with CLC-based labeling-free microfluidic chips is presented.

Recently, label-free liquid crystal (LC) biosensors have been developed. The immunobinding responses are able to re-orient the LC molecules and change their optical signals. The optical property changes of LCs enable naked-eye detection of label-free immunoassays [11]. It was stated that the re-orientating LCs provide sensitivity to immunobinding responses and change the optical signals of LCs [12,13]. A previous study combined LC with microfluidic devices to detect ethanol and bovine serum albumin (BSA) [14,15]. In addition to nematic LCs, cholesteric LCs (CLCs) have unique optical properties like Bragg reflection, bi-stability and flexibility [16,17,18,19,20,21]. The first biologically used CLC sensor device was created by our team in 2015 [22]. A high-sensitivity color-specifying CLC biosensor has been conceived. Nevertheless, the CLC biosensors need complicated fabrication processes and have to be restricted inside a stated area, for instance, a transmission electron microscopic grid [23] or a cell device [24]. To simplify the processes, a single-substrate device has been invented [25]. Furthermore, CLC biosensors can be integrate with a smartphone so it is possible to detect various disease biomarkers at home. Due to the aforementioned advantages, we proposed to integrate CLC materials with microfluidic devices and to investigate the behavior between CLCs and pairs of BSA antigens/antibodies in microchannels [26]. That expedient should enable observing the formation of organic ethanol, but it is just as valid for measuring organic substances. In addition, Fan et al. reported an LC microfluidic system for measuring bimolecular BSA. A robust, unsophisticated appliance for an LC-based microfluidic immunodetecting method has been proposed [27]. The most important related technology of these label-free sensors are grating coupled interferometry (GCI) and plasmonic sensing [28,29,30,31]. However, compared to plasmonic sensing or GCI, LC biosensors are more portable, cheaper and can be monitored with the naked eye [26,27].

Illustration of microfluidic cholesteric liquid crystal (CLC) biological sensor chip in the presence of bovine serum albumin (BSA) biomolecules in DMOAP–coated microfluidic channels. (a) drop the alignment (b) drop the anti-BSA (c) drop the BSA (d) infiltrate the liquid crystals.

CLC-based microfluidic biological sensing chip devices were shown in this investigation. The orientated CLCs were influenced by the surface of the four microchannel walls. The alignment of the DMOAP layer was on the interior of the microchannel, and the CLCs aligned perpendicularly and displayed a blue color reflected under cross-polarizers. Once the antigens of BSA bound onto the BSA [34] antibodies immobilized in the device, the CLC phase color switched from blue to green owing to interruption of the orientation of CLC. The linear range is 0.1–1 mg/mL. By means of pressurized flow, BSA antigen/antibody attachment should be measured with polarized optical microscopy. Moreover, the immune detection limit of BSA antigens/antibodies was 10 ng/mL of BSA and 1000 ng/mL of the anti-BSA antibodies in the CLC device. This suggested that this multiple microfluidic CLC immune assaying chip device could measure BSA and antigens/antibodies of BSA immune complexes with label-free immune detection. The innovative development of this immune assaying device offers a precise, economical, multiple detection, color-specifying and vigorous method for CLC-based immune detection. Based on the results of the CLC biosensor, we may be able to change it for use with anti-SARS-CoV-2 antibodies to capture SARS-CoV-2 and affect the arrangement of CLC as a new sensor. This may have great advantages for coronavirus disease quarantine.

16. Hsiao Y.C., Tang C.Y., Lee W. Fast-switching bistable cholesteric intensity modulator. Opt. Express.2011;19:9744–29749. doi: 10.1364/OE.19.009744. [PubMed] [CrossRef]

17. Hsiao Y.C., Wu C.Y., Chen C.H., Zyryanov V.Y., Lee W. Electro-optical device based on photonic structure with a dual-frequency cholesteric liquid crystal. Opt. Lett.2011;36:2632–2634. doi: 10.1364/OL.36.002632. [PubMed] [CrossRef]

18. Hsiao Y.C., Hou C.T., Zyryanov V.Y., Lee W. Multichannel photonic devices based on tristable polymer-stabilized cholesteric textures. Opt. Express.2011;19:23952–23957. doi: 10.1364/OE.19.023952. [PubMed] [CrossRef]

20. Hsiao Y.C., Lee W. Polymer stabilization of electrohydrodynamic instability in non-iridescent cholesteric thin films. Opt. Express.2015;23:23636–23642. doi: 10.1364/OE.23.022636. [PubMed] [CrossRef]

22. Hsiao Y.C., Sung Y.C., Lee M.J., Lee W. Highly sensitive color-indicating and quantitative biosensor based on cholesteric liquid crystal. Biomed. Opt. Express.2015;6:5033–5038. doi: 10.1364/BOE.6.005033. PubMed] [CrossRef]

25. Chen F.-L., Fan Y.-J., Lin J.-D., Hsiao Y.-C. Label-free, color-indicating, and sensitive biosensors of cholesteric liquid crystals on a single vertically aligned substrate. Biomed. Opt. Express.2019;10:4636–4642. doi: 10.1364/BOE.10.004636. PubMed] [CrossRef]

26. Sutarlie L., Yang K.L. Monitoring spatial distribution of ethanol in microfluidic channels by using a thin layer of cholesteric liquid crystal. Lab Chip.2011;11:4093–4098. doi: 10.1039/c1lc20460b. [PubMed] [CrossRef]

A cholesteric liquid-crystal display (ChLCD) is a display containing a liquid crystal with a helical structure and which is therefore chiral. Cholesteric liquid crystals are also known as Bragg Reflection).

The technology is characterized by stable states i.e. focal conic state (dark state) and planar state (bright state). Displays based on this technology are called “bistable” and don’t need any power to maintain the information (zero power). Because of the reflective nature of the ChLCD, these displays can be perfectly read under sunlight conditions.

A US company, Kent Displays, has developed "no power" Liquid Crystal Displays using Polymer Stabilized Cholesteric Liquid Crystals: these are known as ChLCD screens.mobile phone, allowing it to change colours, and keep that colour even when power is cut off.