Triboelectric nanogenerators (TENGs) have recently shown promising potential as effective energy harvesters using human motion energy. However, the efficiency of polymer-based flexible TENG must be enhanced for various applications. In this work, we propose a flexible TENG with a fluorocarbon plasma-etched polydimethylsiloxane (PDMS)–carbon nanotube (CNT). The fluorocarbon plasma etching causes not only a chemical modification, but also a physical effect on the morphology of the PDMS–CNT surface to enhance the TENG output performance. The added CNT enhances the mechanical properties, such as durability, of a thin film. The etched PDMS structure and the revealed CNTs increase the charge density on the surface. We confirm the effect of different CNT concentrations doped in PDMS and various etching times. We propose a TENG with 4 wt% CNT, which has been subjected to fluorocarbon etching for 60 s. The TENG exhibits an output voltage of 77.8 V, which is 248.7% and 106.5% higher than that of pure PDMS and un-etched PDMS–CNT, respectively. The 20 mm × 30 mm TENG delivers an output power of 1.98 mW (3.29 W m⁻²) at a matching resistance of 3 MΩ. The TENG exhibits good stability and superior electrical performance, making it capable of driving both the instantaneous operation of 70 LEDs and the charging of a 0.33 μF capacitor to 6.6 V. Furthermore, this TENG can be used as a self-powered physical activity sensor that measures the amount of human activity through the amount of charge in the capacitor.

The triboelectric nanogenerator, an energy harvesting device that converts external kinetic energy into electrical energy through using a nano-structured triboelectric material, is well known as an energy harvester with a simple structure and high output voltage. However, triboelectric nanogenerators also inevitably generate heat resulting from the friction that arises from their inherent sliding motions. In this paper, we present a hybrid nanogenerator, which integrates a triboelectric generator and a thermoelectric generator (TEG) for harvesting both the kinetic friction energy and the heat energy that would otherwise be wasted. The triboelectric part consists of a polytetrafluoroethylene (PTFE) film with nano-structures and a movable aluminum panel. The thermoelectric part is attached to the bottom of the PTFE film by an adhesive phase change material layer. We confirmed that the hybrid nanogenerator can generate an output power that is higher than that generated by a single triboelectric nanogenerator or a TEG. The hybrid nanogenerator was capable of producing a power density of 14.98 mW cm ⁻² . The output power, produced from a sliding motion of 12 cm s ⁻¹ , was capable of instantaneously lighting up 100 commercial LED bulbs. The hybrid nanogenerator can charge a 47 μ F capacitor at a charging rate of 7.0 mV s ⁻¹ , which is 13.3% faster than a single triboelectric generator. Furthermore, the efficiency of the device was significantly improved by the addition of a heat source. This hybrid energy harvester does not require any difficult fabrication steps, relative to existing triboelectric nanogenerators. The present study addresses a method for increasing the efficiency while solving other problems associated with triboelectric nanogenerators.

This paper reports an integrated particle detection chip for low-cost and point-of-interest environmental monitoring; it consists of a micro virtual impactor and a micro corona discharger. With this system, airborne particles are introduced into the micro virtual impactor of the chip where they are classified according to their aerodynamic diameters. The particles are then charged and their number-concentration is detected in the micro corona discharger from the electrical current carried by the charged particles. The characteristics of each component were first analyzed, and the components were then integrated into a single chip. The micro virtual impactor was designed to have a cut-off diameter of 600 nm or 1.0 μm. Its classification characteristics were examined by classifying polydisperse particles–dioctyl sebacate particles ranging in diameter from 100 to 600 nm and carbon particles ranging in diameter from 0.6 to 10 μm. From the classification results, the cut-off diameter of the micro virtual impactor was measured to be either 550 nm or 1.1 μm. The micro corona discharger was fabricated based on a sharp silicon tip and a planar electrode and charged particles at 1.3 kV. Using the integrated particle detection chip comprising the micro virtual impactor and the micro corona discharger, the sensitivity for monodisperse particles—500 nm dioctyl sebacate in diameter—was measured to be 8 × 10⁻⁷ pA/(particle cm⁻³).

In this paper, a thermoelectric generator that embeds phase change materials for wasted heat energy harvesting is proposed. The proposed thermoelectric generator embeds phase change materials in its device structure. The phase change materials store large amounts of heat energy using the latent heat of fusion. When the heat source contacts the thermoelectric generator, dissipated heat from the heat source is stored in the phase change materials. When the heat source is removed from the thermoelectric generator, the output power of the thermoelectric generator slowly decreases, while the output power of conventional thermoelectric generators decreases rapidly without the heat source. The additional air layer in the proposed thermoelectric generator disturbs the heat dissipation from the phase change materials, so the thermoelectric generator can maintain the power generation for longer without a heat source. The experimental results for the thermoelectric generator fabricated clearly show the latent heat effect of the phase change materials and the embedded air layer.

Phosphatidylserine (PS) is an important anionic phospholipid that is synthesized within the endoplasmic reticulum (ER). While PS shows the highest enrichment and serves important functional roles in the plasma membrane (PM) but its role in the nucleus is poorly explored. Using three orthogonal approaches, we found that PS is also uniquely enriched in the inner nuclear membrane (INM) and the nuclear reticulum (NR). Nuclear PS is critical for supporting the translocation of CCTα and Lipin1α, two key enzymes important for phosphatidylcholine (PC) biosynthesis, from the nuclear matrix to the INM and NR in response to oleic acid treatment. We identified the PS-interacting regions within the M-domain of CCTα and M-Lip domain of Lipin1α, and show that lipid droplet formation is altered by manipulations of nuclear PS availability. Our studies reveal an unrecognized regulatory role of nuclear PS levels in the regulation of key PC synthesizing enzymes within the nucleus.

Growing concerns related to the adverse health effects of airborne ultrafine particles (UFPs; particles smaller than 300 nm) have highlighted the need for field-portable, cost-efficient, real-time UFP dosimeters to monitor individual exposure. These dosimeters must measure both the particle density and size distribution as these parameters are essential to the determination of where and how many UFPs will be deposited in human lungs. However, though various kinds of laboratory-grade instruments and hand-held monitors have been developed, they are expensive and only capable of measuring particle size distribution. A microfluidic UFP dosimeter is proposed in this study to address these limitations. The proposed sensor, based on an electrical detection method with a machine-learning-aided algorithm, can simultaneously measure the size distribution (number concentration, mean mobility diameter, geometric standard deviation) and particle density, and is compact owing to the microelectromechanical systems (MEMS) technology. In a comparison test using physically synthesised Ag and di-ethyl-hexyl sebacate (DEHS) aerosols, the mean measurement errors of the proposed sensor compared to the reference system were 6.1%, 4.5%, and 7.3% for number concentration, mean mobility diameter, and particle density, respectively. Moreover, when the machine-learning aided algorithm was operated, the geometric standard deviation could be deduced with a 7.6% difference. These results indicate that the proposed device can be successfully used as a field-portable UFP sensor to assess individual exposure, an on-site monitor for ambient air pollution, an analysis tool in toxicological studies of inhaled particles, for quality assurance of nanomaterials engineered via aerosol synthesis, etc.