Harvesting a Sustainable Energy Future: Examining the effect of chemical composition on the electromechanical properties of polymer gel beads

Clean energy is required to ensure global prosperity and economic growth. Increased industrialization is expected to increase energy demand by 50% by 2035. This will result in increased air pollution. Carbon dioxide emissions have been linked to global warming and other pollution related problems. These emissions can be reduced by recapturing the waste energy in the form of heat, vibration, and friction. Common applications like transportation can lose as much as 78% of the energy they generate. Energy harvesters can be used to recapture energy lost through vibration, heat, etc. This recaptured energy will be reused and hence, we don’t need to produce as much energy using traditional methods. Equipment with low power needs such as sensors can use this recaptured energy and hence, the need for external battery or energy source will be minimized. This investigation will focus on the effects of chemical composition on the electromechanical properties of the gel beads. Electrostatic energy harvesters consist of a proof mass that translates or deforms relative to an electrode array. When an electrical field is applied, this causes a change in capacitance which drives a current through a load resistance to generate power. Ionic liquid polymers have been used in dye-sensitized solar cell energy harvesters. This work will examine whether the flexibility offered by Polymeric Ionic liquid (PIL) gel beads could be leveraged in other energy harvesting devices. To that end, this investigation works to examine the effect of the chemical composition of PIL beads on electromechanical properties. This will be accomplished using: 1. Microfluidic fabrication of conductive gel beads 2. Experimental testing of electromechanical properties of the beads 3. Metallization of IL resins and IL gel beads fabricated from the microreactor. 4. Optimization of those properties through a chemical understanding of the components required for use in electrostatic energy harvesters. The IL beads are fabricated and tested for electromechanical properties to study the effects of the percentage of IL present in the chemical composition of the monomer solution. As the IL proportion was decreased, the gel beads had stronger physical properties such as stiffness but poor conductivity. To improve their conductivity, these IL gel beads were metallized with a gold salt solution. In metallization process, Cl- ions of the IL were replaced by gold AuCL4- ions which were subsequently reduced to Auo with the agency of Hydrazine. The metallization process resulted in significant increase in conductivity of the IL gel beads

Highly directional and coherent emission from dark excitons enabled by bound states in the continuum

A double-edged sword in two-dimensional material science and technology is an optically forbidden dark exciton. On the one hand, it is fascinating for condensed matter physics, quantum information processing, and optoelectronics due to its long lifetime. On the other hand, it is notorious for being optically inaccessible from both excitation and detection standpoints. Here, we provide an efficient and low-loss solution to the dilemma by reintroducing photonics bound states in the continuum (BICs) to manipulate dark excitons in the momentum space. In a monolayer tungsten diselenide under normal incidence, we observed a giant enhancement with an enhancement factor of ~3,100 for dark excitons enabled by transverse magnetic BICs with intrinsic out-of-plane electric fields. By further employing widely tunable Friedrich-Wintgen BICs, we demonstrated highly directional emission from the dark excitons with a divergence angle of merely 7 degrees. We found that the directional emission is coherent at room temperature, unambiguously shown in polarization analyses and interference measurements. Therefore, the BICs reintroduced as a momentum-space photonic environment could be an intriguing platform to reshape and redefine light-matter interactions in nearby quantum materials, such as low-dimensional materials, otherwise challenging or even impossible to achieve

Engineering photonic environments for two-dimensional materials

A fascinating photonic platform with a small device scale, fast operating speed, as well as low energy consumption is two-dimensional (2D) materials, thanks to their in-plane crystalline structures and out-of-plane quantum confinement. The key to further advancement in this research field is the ability to modify the optical properties of the 2D materials. The modifications typically come from the materials themselves, for example, altering their chemical compositions. This article reviews a comparably less explored but promising means, through engineering the photonic surroundings. Rather than modifying materials themselves, this means manipulates the dielectric and metallic environments, both uniform and nanostructured, that directly interact with the materials. For 2D materials that are only one or a few atoms thick, the interaction with the environment can be remarkably efficient. This review summarizes the three degrees of freedom of this interaction: weak coupling, strong coupling, and multifunctionality. In addition, it reviews a relatively timing concept of engineering that directly applied to the 2D materials by patterning. Benefiting from the burgeoning development of nanophotonics, the engineering of photonic environments provides a versatile and creative methodology of reshaping light–matter interaction in 2D materials