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Generally speaking, the aerodynamic force generated by each component will hinder the endurance and performance of the UAV. In addition, because PVDF has the characteristics of high flexibility, corrosion resistance and nontoxic, a wind resistance pro-filed sensor based on polyvinylidene fluoride (PVDF) is developed, which can be used to measure the resistance of UAV in different directions. The sensor consists of nine surfaces, which can measure the resistance caused by wind in different directions at the same time. By analyzing the average output voltage collected under different wind speeds and flight states, the resistance of different UAV propellers is estimated. This research is helpful to improve the structure of UAV, reduce the impact of drag, and increase the UAV's endurance time and carrying capacity. [ABSTRACT FROM AUTHOR]

Polyvinylidene fluoride (PVDF) membranes is a new ferroelectric material exhibiting large piezoelectric properties and has desirable attention in biosensors and the healthcare field. A set of wearable belt was developed using PVDF films of 28 μm as sensitive element and conductive silver as the electrodes. The equipment was designed such that it can sense vibration which could be compatible to those produced by human sleep signal (SS) in a noninvasive way. The prototype of the wearable belt which has 1 × 24 parallel curved slender beams (CSBs) as sensing element using 28 μm thickness PVDF film was fabricated. The element is an assembly of layered media. The base of the sensitive element is a hyperelastic inferior arc polyhedron, on which a PVDF film with silver electrode patches, two 5 μm copper-clad signal interfaces attached to both sides of the PVDF film using conductive adhesive, and a protective surface layer of polyester film for insulation are stacked in sequence. The role of the polyhedron, copper surface end and parallel CSBs design to enhance detection signals, and the capability of the sensor to faithfully detect the SS were experimentally evaluated. Results showed that the new wearable belt (WB) has been manufactured to sense the SS including heartbeat rate (HR), respiration rate (RR) as well as postural signal (PS), and its sensitivity to external mechanical force or vibration is 1.5 times higher than that of a sheet sensitive structure device. All these experimental set-up proposed and developed by us showed the remarkable contribution of the sensitivity and repeatability (98.6%) in SS monitoring depending on signal characteristics such as frequency and amplitude. [ABSTRACT FROM AUTHOR]

In present work, semi-crystalline polyvinylidene fluoride (PVDF) films of 5 wt%, 10 wt%, and 15 wt% PVDF solution is deposited on the glass substrate by spin coating technique at 500, 1000, and 1500 rpm speed. For deposition of the film, the polymeric solution is prepared by dissolving PVDF powder in the polar solvent of N,N-dimethylformamide solvent. The effect of different PVDF content and spin coating speed on the microstructural evolutions in the produced film is investigated by using FE-SEM, AFM, and FTIR spectrometer. The optical properties of the film are also investigated by the UV-vis spectrometer. [ABSTRACT FROM AUTHOR]

Tactile is defined as a continuous sensing of variable contact forces, heat transfer, slippage, and various stimuli producing pain. The contact force and slip are the primary information measured by tactile sensor. In this paper, a detailed review of the tactile sensors for detecting contact force and slip based on polyvinylidene fluoride (PVDF) piezoelectric films is presented. When a touch and relative motion occur between the sensor and an object, the PVDF film can induce an electrical field across its boundaries. Hence, the PVDF sensors are suitable for contact force and slip detection. In addition, the PVDF has numerous advantages especially the high sensitivity, large electro-mechanical transduction frequency bandwidth, high elastic permittivity, light weight and low cost. Therefore, the tactile sensor by PVDF can be developed as a versatile tool for automation applications such as the sensor systems of robotic gripper. The review describes specific information on the definition of piezoelectricity, the principle of piezoelectric signal by PVDF film, the structural design of various PVDF-based tactile sensors, the hardware and software design of tactile sensing system, as well as some typical applications of the PVDF tactile sensors in different electromechanical devices. [ABSTRACT FROM PUBLISHER]

This paper reviews wearable and unconstrained systems based on PVDF sensors in physiological signals monitoring. Since using wearable and unconstrained biomedical sensor systems for health monitoring is convenient and efficient, and piezoelectric polyvinylidene fluoride (PVDF) film has the advantages as flexibility, wide frequency response, low cost, easiness to fabricate, biocompatibility and light weight, many studies have focused on the PVDF film as sensors of wearable and unconstrained systems. Utilizing a modular design concept, the processing circuit of systems can be reorganized to implement different functions, so as to match different medical applications. This paper reviews key ideas and performance of the reported wearable and unconstrained systems based on PVDF sensors in physiological signals monitoring and the modular design concept. The various existing state of art practices of the wearable and unconstrained systems with PVDF sensors in measurement of physiological signals are also reviewed. And an outlook of the future about wearable and unconstrained systems with PVDF sensors in physiological signals monitoring is given. [ABSTRACT FROM AUTHOR]