Light Control Function Research Articles

Photoresponsive Supramolecular Polymers: From Light-Controlled Small Molecules to Smart Materials.

Photoresponsive supramolecular polymers are well-organized assemblies based on highly oriented and reversible noncovalent interactions containing photosensitive molecules as (co-)monomers. They have attracted increasing interest in smart materials and dynamic systems with precisely controllable functions, such as light-driven soft actuators, photoresponsive fluorescent anticounterfeiting and light-triggered electronic devices. The present review discusses light-activated molecules used in photoresponsive supramolecular polymers with their main photo-induced changes, e.g., geometry, dipole moment, and chirality. Based on these distinct changes, supramolecular polymers formed by light-activated molecules exhibit photoresponsive disassembly and reassembly. As a consequence, photo-induced supramolecular polymerization, "depolymerization," and regulation of the lengths and topologies are observed. Moreover, the light-controlled functions of supramolecular polymers, such as actuation, emission, and chirality transfer along length scales, are highlighted. Furthermore, a perspective on challenges and future opportunities is presented. Besides the challenge of moving from harmful UV light to visible/near IR light avoiding fatigue, and enabling biomedical applications, future opportunities include light-controlled supramolecular actuators with helical motion, light-modulated information transmission, optically recyclable materials, and multi-stimuli-responsive supramolecular systems.

Switching daylight: Performance prediction of climate adaptive ETFE foil façades

This paper reports on the daylighting performance of switchable ethylene-tetrafluoroethylene (ETFE) foil in double-skin façades (DSF). In contrast to conventional glazing or static ETFE façades, switchable ETFE moderates incident daylight and controls internal light distribution by actively responding to weather conditions and solar light intensity. To better understand the light control function of ETFE and the impact of parameters such as climate, latitude and window-to-wall ratios (WWR), a validated optical model was used to evaluate different DSF designs. ETFE façades were modelled with a Bidirectional-scattering distribution-function (BSDF) and spectral data, obtained from experimental measurements, to accurately represent specular and diffuse light transmittance. Based on the five-phase method, a parametric climate data-driven simulation of an office room with different façade designs was conducted for three climate scenarios (Oceanic, Mediterranean, Sub-Tropical). When employing switchable ETFE in façades with different WWRs (30–90%), an annual increase of useful daylight illuminance (UDI) from 11 to 69% in the range of 500–2000lx was recorded. The calculated glare probability (DGPs) declined 59% in the best-case scenarios, providing working conditions with imperceptible glare for 94% of the scheduled time. Simultaneously, the daylight uniformity ratio (UR) increased up to 19% compared to a room with a conventional double-glazed façade. Significant improvements of daylight quality were achieved for façades with large windows in climates with abundant solar light available all year long. Overall, this study contributes to expanding the knowledge on adaptive membrane façades, demonstrating their capacity to enhance the daylighting performance of indoor spaces in different climates.

Greenhouse cover plate with dimming and temperature control function

A new type of greenhouse cover plate with light and temperature control function is proposed. The optical software is used to simulate the concentrating characteristics of the cover plate. The simulation results show that the new cover plate has the characteristics of higher receiving rate when the incident angle is small, higher transmittance when the incident angle is large, and this tendency is more obvious when the position of fluid channel become higher and the radius become smaller. The experimental samples were processed and the acceptance rate and transmission rate were tested in typical sunny weather. The experimental and simulation results are matched well. At noon, the transmittance of the new cover plate reaches about 35% of the lowest in a day, while that of the double glass cover plate is about 70%. This new type of cover can not only realize the light control function, but also realize the efficient thermal utilization of solar energy, so it has a broad application prospect.

Reconfigurable and tunable photo-controlled hydrogel using hydrogen bonding to drive molecule self-assembly and cross-linking

Reconfigurable micro–nanostructures have been largely used in the development of modern photocontrol technology. In this work, a dynamically adjustable hydrogel of supramolecule structures is realized by molecule self-assembly and cross-link in microscale. Calculations based on the molecule modeling systematically illuminate the assembly process and the mechanism of the dynamically adjustable micro–nanostructure. The transmittance changes of the hydrogel, which are measured in the visible-light range before and after electric heating, show outstanding light-control function. Thus, the one-step fabrication, bio-compatibility (no initiator, cross linker, or monomer residual), and agile photocontrol application demonstrate the potential of the adjustable physically bonded hydrogel in development of low-loss and integrated dynamical light-control devices.

Performance study of a new type of transmissive concentrating system for solar photovoltaic glass curtain wall

There are many problems in Building Integrated Photovoltaics (BIPV) system, such as contradiction between daylighting and electricity generation, unable to match the demand of light control, need to constantly adjust angle for tracking, and so on. A new type of transmissive concentrating system for glass curtain wall is proposed which can improve the performance of solar photovoltaic glass curtain wall. The concentrating characteristic was studied by a series of comprehensive simulation and experiment. The optical software is used to simulate the influence of concentrating characteristics in different incident angles. Compared with solid and trapezoidal structure compound parabolic collector, the concentrating performance of hollow with water structure is also simulated. Simulation results shown that the receiving rate of hollow with water compound parabolic collector is changing slowly when incidence angle is increasing between 0 and 20°, and it can achieve 70% when the incidence angle less than 20°, and it is better than other concentrator with different cross section shapes. Based on simulation results, the experimental samples were processed and tested in a typical sunny weather. The experimental results were in good agreement with the simulation results. The system had a minimum transmittance of 28.2% at noon, but before 9:40 AM and after 15:40 PM, the transmittance exceeds 55% and can meet lighting requirements of rooms. It can be proved that the new system has passive light control function, which is expected to replace the double-layer vacuum glass curtain wall that is widely used nowadays.

Photo-responsive liquid crystalline vitrimer containing oligoanilines

Liquid crystalline vitimers (LC-vitrimers) can be easily processed into complex three-dimensional configurations. In this paper, we present a photo-responsive LC-vitrimer by simply introducing a photo-thermal agent aniline trimer into the LC-vitrimer system. As aniline trimer acts as a curing agent, it can be homogeneously dispersed in the material, avoiding aggregation which commonly happens to nano-fillers. As a result, the resultant polymer not only can perform three light-controlled functions (welding, healing and shape memory), but also can be prepared into aligned monodomain LC actuators with strains of about 40%–45%.

315 高分子フィルムを用いた遮熱カーテンの多層構造最適設計に関する検討(OS1-2 最適設計と解析)

For residential windows, transparency and lighting properties are required at the same time. It is also necessary to have thermal barrier ability. To achieve both transparency and thermal barrier effect, it is necessary to control independently the transmission of visible light and near-infrared light spectrum. If the curtain having such a light control function by loading the window of the housing, windows can achieve high functionality at low cost. In this study, optimum design of a multilayer film structure that can transmit visible light and shield against heat.

Flowering time regulation: photoperiod- and temperature-sensing in leaves

Plants monitor changes in photoperiod and temperature to synchronize their flowering with seasonal changes to maximize fitness. In the Arabidopsis photoperiodic flowering pathway, the circadian clock-regulated components, such as FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 and CONSTANS, both of which have light-controlled functions, are crucial to induce the day-length specific expression of the FLOWERING LOCUS T (FT) gene in leaves. Recent advances indicate that FT transcriptional regulation is central for integrating the information derived from other important internal and external factors, such as developmental age, amount of gibberellic acid, and the ambient temperature. In this review, we describe how these factors interactively regulate the expression of FT, the main component of florigen, in leaves.

Study of Energy Saving Lamp System for Sound and Light Double Control

The main content of intermittent lamp energy saving technology study in small public places is the circuit control system. A lamp energy saving control circuit system is developed and designed by using the timer 555 modules, Silicon controlled technology, power supply circuit, photosensitive and audio sensor module, etc. The system has sound and light double control and timing function, photosensitive and audio sensing circuit dormancy and lamp shut off during the day or light is good. In the evening or subtle lighting, photosensitive and audio sensors are opened at the same time, lamp working for 20 seconds through the human voice incentive and automatically shut off. The application and test show that the system circuit has low power consumption and strong generality promotion, and realizes the purpose of energy saving.

Angular and spectral sensitivity of fly photoreceptors. III. Dependence on the pupil mechanism in the blowfly Calliphora.

A wave optics model for the facet lens-rhabdomere system of fly eyes is used to analyze the dependence of the angular and spectral sensitivity of R1-6 photoreceptors on the pupil mechanism. This assembly of light-absorbing pigment granules in the soma interacts with the waveguide modes propagating in the rhabdomere. A fly rhabdomere carries two modes in the middle wavelength range and four modes at short wavelengths, depending on the rhabdomere diameter and the angle of the incident light flux. The extension of the mode to outside the rhabdomere strongly depends on wavelength, and this dependence plays a determinant role in the light control function of the pupil. The absorbance spectrum of the pigment in the pupil granules is severely depressed at short wavelengths by waveguide effects, resulting in a distinct blue peak. Accordingly, pupil closure suppresses the photoreceptor's spectral sensitivity much more in the blue-green than in the UV. The pupil only narrows the angular sensitivity at short wavelengths. The geometrical size of the rhabdomere governs the angular sensitivity of fly photoreceptors in the dark-adapted state, but diffraction takes over in the fully light-adapted state.