Lighting has been used for a long time as a medium to convey brightness from darkness, and through incandescent lamps and fluorescent lamps, LED light sources have now become the standard in the lighting industry. Recently, the lighting equipment industry has been undergoing rapid digital transformation, starting with smart lighting, and is evolving into smart lighting customized for individuals and spaces through the development of IoT technology, cloud-based services, and data analysis. However, the blue light emitted from digital devices (computers, smartphones, tablets, etc.) or LED lights stimulates the melanopsin in the optic ganglion cells in the retina of the eye, which in turn stimulates the secretion of melatonin through the pineal gland, which regulates the secretion of melatonin. This can reduce sleep quality or disrupt biological rhythms. This interaction between blue light and melatonin has such a significant impact on human sleep patterns and overall health that it is essential to reduce exposure to blue light, especially in the evening. Human-centered lighting refers to lighting that takes into account the effects of light on the physical and mental areas, such as human activity and awakening, improvement of sleep quality, and health management. Many research institutes study the effects in the visible area and the non-visible area. By studying the impact, it is expected to improve the quality of human life. In this study, we plan to study ways to implement humancentered lighting by collecting sunrise and sunset data and linking commercialized LED packages and control devices with opensource hardware.

An excellent hydrophobic surface has a high contact angle over 147 degree and the contact anglehysteresis below 50 was produced by using roughness combined with hydrophobic PTFE coatings, which were alsoconfirmed to exhibit an extreme adhesion to glass substrate. To form the rough surface, the glass was etched byAr-plasma. A very thin PTFE film was coated on the plasma etched glass surface. Roughness factors before orafter PTFE coating on the plasma etched glass surface, based on Wensel``s model were calculated, which agreeswell with the dependence of the contact angle on the roughness factor is predicted by Wensel``s model. The PTFEfilms deposited on glass by using a conventional rf-magnetron sputtering. The glass substrates were etchedAr-plasma prior to the deposition of PTFE. Their hydrophobicities are investigated for application as a anti-foulingcoating layer on the screen of displays. It is found that the hydrophobicity of PTFE films mainly depends on thesputtering conditions, such as rf-power, Ar gas content introduced during deposition. These conditions are closelyrelated to the deposition rate or thickness of PTFE film. Thus, it is also found that the deposition rate or the filmthickness affects sensitively the geometrical morphology formed on surface of the rf-sputtered PTFE films. Inparticular, 1,950-nm-thick PTFE films deposited for 30 minute by rf-power 50 watt under Ar gas content of 20sccm shows a very excellent optical transmittance and a good anti-fouling property and a good durability.

Super-hydrophobic properties have been achieved on the rf-sputtered polytetrafluoroethylene(PTFE) films deposited on etched aluminum surfaces. The microstructural evolution created after etching has been investigated by FESEM. The water contact angle over 160o can be achieved on the rf-sputtered ultra-tihn PTFE film less than 10 nm coated on aluminum surface etched with 7 wt.%, 12.5 wt.%, and 15 wt.% HCl concentration for 12 min. XPS analysis have revealed the presence of a large quantity of -CF3 and -CF2 groups in the rf-sputtered PTFE films that effectively can reduce the surface energy of etched aluminum. The presence of patterned morphology along with the low surface energy at the rf-sputtered PTFE coating makes the aluminum surface with high super-hydrophobic property.