Reaching High Piezoelectric Performance with Rotating Directional-Field-Aligned PVDF-MoS2 Piezo-Polymer Applicable for Large-Area Flexible Electronics.

Wearable electronics and smart harvesting textile studies require a material system that resists physical stimulation. Such applications require receptive piezo-polymers, and their activation-free preparation that can translate into a continuous large-area film. In this work, it is discussed whether the ß-content of piezo-polymer is extended with no use of any activation (i.e. poling), and if the ß-content increases, it can be processed over a wide range of surfaces like large-area piezo-film. Such prerequisites within polyvinylidene fluoride-molybdenum disulfide ((PVDF)-MoS2 ) piezo-polymer are thoroughly experimented here to develop a high-performance piezo-film. A MoS2 -mediated PVDF piezo-polymer (termed as P+ -MoS2 ) is introduced, in which no extra ß-enhancement activation step is required after spin coating. Experimental results record ß â‰§ 80% which allows to harvest the voltage and current in the level of ≈17 V and 1 µA, respectively which satisfies 5 V supply voltage requirement of the current microelectronics, and internet of things (IoT). In addition, the capacitors having different capacities are charged using the developed nanogenerator to check its practical applicability. Therefore, the transition process of P-MoS2 to aligned P+ -MoS2 due to passive interlocking (PiL) through rotating directional field is novel and found to be a principal reason for ß-enhancement in fabricated devices.

A highly precise cross-capacitive sensor for metal debris detection in insulating oil.

The presence of metal particles in lubricating oil produced during the wear and tear of mechanical equipment can harm its performance severely if not detected in time. Hence, the detection of such particles is necessary to predict and to prevent disastrous failures of the machines. This paper presents a new non-contact cross-capacitive sensor for the detection of metal particles in the lubricating oil. The sensor can detect each and every metal debris particle in the lubricating oil by monitoring the capacitance peak. The proposed capacitive sensor works on the principle of the Thompson-Lampard theorem. The sensor consists of four cylindrical electrodes with infinitesimal gaps wrapped around a hollow Teflon tube. The sensor has been modeled with finite element simulation software and then fabricated to verify the theory experimentally. Experimental results show that the capacitance value shows a sharp change in its value due to the presence of metal debris in the oil. The output of the sensor is highly precise (±0.82%) and accurate.