Optimizing textiles for enhanced passive radiative thermoregulation properties represents a significant step forward in technological innovation. To achieve this goal, we fabricated and characterized a visible-opaque infrared-modulator fabric (VOIMF) that can provide the human body with continuous thermoregulation at low temperatures. The fabric is a bilayer emitter composed of a polyethylene (PE) membrane and an ultrathin gold (Au) layer. The PE membrane contains randomly dispersed titanium dioxide (TiO2) microparticles (MPs). By flipping the fabric, we demonstrate that the VOIMF can modulate the emissivity toward the environment in the mid-infrared range, thereby providing a thermal comfort zone over a large temperature range of ∼ 10 °C (from 6.7 to 16.8 °C). Moreover, the VOIMF is opaque in the visible (VIS) range and exhibits a white appearance, similar to cotton, due to the high light scattering property of TiO2 MPs.

The development of textiles for personal thermal management is one of the most promising technological solutions to reduce the energy consumption in heating, ventilation, and air conditioning (HVAC) systems. These technologies offer a potentially low-cost solution that can help to limit greenhouse gas emissions. In this paper, we propose the design and fabrication of a polyimide (PI)-based microstructured photonic membrane (MSPM) for personal passive heating textile. Using a photolithographic process, the membrane is drilled with a triangular array of holes. We showed theoretically and experimentally that the MSPM can decrease the transmission of mid-infrared (MIR) radiation emitted by the human body. The thermoregulator effect of the MSPM is demonstrated by using a thermal camera and a thermocouple. This fabric can efficiently warm the human body, enabling lower room temperature while still maintaining personal comfort. Moreover, the microholes enable air permeability and promote water-wicking. The performance of this membrane provides a new opportunity to deploy thermal management textiles for everyday use and targets one of the major forms of energy consumption.

Improving radiative heating performance of textiles is becoming one of the most current research topics to reduce the energy consumption used to control the indoor areas temperature. In this work, the properties of a textile‐based asymmetric design for radiative heating are studied both theoretically and experimentally, and its remarkable efficiency over a wide range of temperature is demonstrated. By sandwiching a thin metallic layer characterized by a high reflectivity in the mid‐infrared (MIR) between two polyethylene (PE) membranes of same thickness, it is proposed to control the MIR emissivity of the structure by the introduction of SiO 2 nanoparticles (NPs) in one of the two PE membranes. By reversing the fabric side to side, a wide comfort zone can be achieved for medium and low ambient temperatures, typically between 7.1 and 16.3 ° C. Moreover, it is shown that, when transferred on a regular textile, the fabric performs the same functionalities. The experimental demonstration is done by considering an equivalent asymmetric structure with thicker membranes, without NPs. The fabrication and characterization processes are reported and a good agreement is obtained between the Fourier transform infrared spectra and the numerical data.

Personal thermal management represents a new paradigm to reduce the energy consumption, which consists in controlling the temperature around the human body rather than regulating the temperature of the entire residential space. Recent progress in smart textile showed promising radiative heating and cooling performance. However, propositions for double functional textiles, namely cooling and heating, are still limited. We present here a theoretical study of a dynamic thermoregulatory fabric (DTF) able to regulate the human body temperature by adapting its geometry. The DTF is a 2D photonic crystal constituted of an ultra-thin metallic film sandwiched between two temperature-sensitive polymer membranes. The stacked geometry is drilled with air holes according to a triangular array. We demonstrate that the DTF is able to maintain the thermal comfort over a wide range of room’s temperature by dynamically controlling the mid infrared (MIR) radiations of the human body.

Keeping the human body in a thermal comfort state inside a room has become a challenge in recent years. While the most common strategy is to heat buildings, it requires a lot of energy. Reducing this energy consumption will have positive impacts, both economically and environmentally. We propose here to act directly on the personal thermal heating of the human body, by modulating the absorption and transmission properties of a synthetic polymer membrane in the mid-infrared (MIR). We show numerically that 5% SiO2 submicron particles inserted in polyethylene (PE) and nanoporous polyethylene (nanoPE) membranes increase the radiative heating of the membrane, reducing the required ambient temperature of a room by more than 1.1 °C. The proposed membrane can be flexible enough to be easily integrated into conventional textiles.

We study the optical properties of a polymer photonic membrane to keep the human body in thermal comfort. We show theoretically that the periodic structuration of the membrane with air holes modulates the optical response in the Mid-Infrared range. We found that the modulation of the optical spectrum allows to decrease the required ambient temperature by about 0.5 °C to maintain the normal skin temperature of 34 °C. The structured membrane is flexible and can easily be added to usual textiles. Keywords-photonic membrane; Mid-Infrared; thermal comfort.

Mixed TixSi1-xO2 oxide can exhibit a partial phase separation of the TiO2 and SiO2 phases at the atomic level. The quantification of TiO2-SiO2 mixing in the amorphous material is complicated and was so far done mostly by infrared spectroscopy. We developed a new approach to the fitting of X-ray photoelectron spectroscopy data for the quantification of partial phase separation in amorphous TixSi1-xO2 thin films deposited by plasma enhanced chemical vapour deposition. Several fitting constraints reducing the total number of degrees of freedom in the fits and thus the fit uncertainty were obtained by using core electron binding energies predicted by density functional theory calculations on TixSi1-xO2 amorphous supercells. Consequently, a decomposition of the O is peak into TiO2, SiO2 and mixed components was possible. The component areas ratios were compared with the ratios predicted by older theoretical models based on the atomic environment statistics and we also developed several new models corresponding to more realistic atomic structure and partial mixing. Based on the comparison we conclude that the studied films are mostly disordered, with only a moderate phase separation.

We study numerically the absorption and scattering properties of a polymer photonic membrane to thermoregulate the human body microclimate which corresponds to the area between the skin and a textile. We first show that the structuration of the absorbing photonic membrane with air holes leads to a modulation of the optical spectrum in the Mid-Infrared range. Indeed, we show that the membrane is able to modulate the transmission amplitude by 28% in benefit or deficit of both the absorption and reflection. We then studied the thermal balance between the human body and the surrounding environment through the photonic membrane. We found that, compared to a regular membrane, the photonic crystal structure behaves as a heating component that offers the possibility to reduce the temperature of the room up to +1 °C. The membrane is flexible, low cost, 3D-printable, free of metallic particles, and can easily be added to usual textiles.

TiO2-SiO2 mixed oxide films with variable compositions are deposited from oxygen/titanium tetraisopropoxide/hexamethyldisiloxane (HMDSO) inductively coupled radiofrequency plasmas at low temperature and pressure. The related structure, morphology, and optical properties are investigated. Results show that the [Si]/[Ti + Si] concentration ratio in the film is increased sharply from 0 (pure TiO2) to 0.48 by adding a small amount of HMDSO. The mixed films are in amorphous phase, and the formation of Ti-O-Si is revealed. With an increase of Si content: the columnar structure of TiO2 disappears, the whole film seems to be homogeneous and more compact, the grain size decreases and the top surface becomes smoother; both the refractive index and extinction coefficient are decreased, while the bandgap is increased.

L'objectif de cette etude est l'evaluation des potentialites de la nanophotonique a fort contraste d'indice pour la realisation de deux fonctions optoelectroniques hyperfrequences : une fonction retard variable et un interrupteur tout optique ultrarapide. Nous proposons l'utilisation de nanofils d'InP inseres dans une matrice de faible indice optique en benzocyclobutene par report de substrat. Cette structure beneficie des proprietes des materiaux III-V pour la realisation de fonctions actives. La realisation d'une telle structure passe par l'optimisation d'un procede technologique de haute resolution, pour palier la forte sensibilite des nanofils a toute variation de taille. La qualite de la technologie employee a ete demontree par la caracterisation optique de nos structures, avec la mise en evidence de pertes de propagation inferieures a 10 dB/cm et d'une reduction importante des pertes de couplage. Les caracteristiques ainsi obtenues font des nanofils d'InP dans le BCB une structure de qualite pour la realisation de fonctions actives et nous permettent d'etudier les phenomenes physiques a l'origine des fonctions envisagees. Ainsi, la faisabilite de reseaux de Bragg sur nanofil d'InP dans le BCB a pu etre mise en evidence et leur potentialite pour la creation de retards hyperfrequences lies au phenomene de lumiere lente a ete evaluee a environ 1 ns pour des reseaux de 1 mm de long. Par ailleurs, le phenomene de saturation d'absorption a egalement ete demontre et permettra la creation d'un interrupteur tout optique. En outre, des pistes ont ete proposees pour assurer le caractere ultrarapide et en diminuer la puissance de commande.

High index contrast waveguides in the III-V material line are demonstrated here. Created thanks to a wafer bonding technology, they are made of a GaAs nanowire embedded in a benzocyclobutene (BCB) matrix. We also report some of those waveguides properties and an example of active device considered with this technology.

We expose the technological process to realize III-V semiconductor optical nanowires embedded in a Benzocyclobutene (BCB) matrix based on adhesive wafer bonding. We also point out some properties of those nanophotonic waveguides to develop all optical switches.

Our research interest is the fabrication of high index contrast waveguides in III-V material for nanophotonic applications at telecom wavelengths (1.3 or 1.55 µm). We propose to create this high index contrast by embedding a III-V nanowire in a low index polymer matrix (Benzocylobutene, BCB). We expose here the simple wafer bonding processing technique that leads to these III-V nanowires buried in BCB.