Composites, Fabrication and Application of Polyvinylidene Fluoride for Flexible Electromechanical Devices: A Review

Abstract

The technological development of piezoelectric materials is crucial for developing wearable and flexible electromechanical devices. There are many inorganic materials with piezoelectric effects, such as piezoelectric ceramics, aluminum nitride, and zinc oxide. They all have very high piezoelectric coefficients and large piezoelectric response ranges. The characteristics of high hardness and low tenacity make inorganic piezoelectric materials unsuitable for flexible devices that require frequent bending. Polyvinylidene fluoride (PVDF) and its derivatives are the most popular materials used in flexible electromechanical devices in recent years and have high flexibility, high sensitivity, high ductility, and a certain piezoelectric coefficient. Owing to increasing the piezoelectric coefficient of PVDF, researchers are committed to optimizing PVDF materials and enhancing their polarity by a series of means to further improve their mechanical–electrical conversion efficiency. This paper reviews the latest PVDF-related optimization materials, related processing and polarization methods, and the applications of these materials such as those in wearable functional devices, chemical sensors, biosensors, and flexible actuator devices for flexible micro-electromechanical devices. We also discuss the challenges of wearable devices based on flexible piezoelectric polymer, consider where further practical applications could be.

Orientation-controlled crystallization of γ-glycine films with enhanced piezoelectricity

“…6 Limitations of conventional piezoelectric materials encouraged the emergence of novel biological piezoelectric materials with high flexibility, desired biocompatibility and biodegradability. 7,8 Amino acids, a fundamental building block of the human body and one of the simplest biomaterials, are recently re-emerged as a promising piezoelectric biomaterial 7,9,10 with theoretical piezoelectric coefficients comparable to conventional piezoelectric soft materials such as polyvinylidene difluoride (PVDF) 11 and zinc oxide. 12 In addition, most types of amino acids are piezoelectric due to their non-centrosymmetric crystal structures.…”

Recent Advances in Microfluidic Devices for Contamination Detection and Quality Inspection of Milk

“…For example, the detection of heavy metal residues in milk requires high-sensitivity detection with a LOD on the order of ppb. Such applications generally require the use of high-resolution detection systems such as fluorescence, electrochemistry (EC), electrophoresis (EP), surface-enhanced Raman spectroscopy (SERS), and so on [ 25 , 26 , 27 ]. However, many alternative quantitative detection systems have also been proposed in recent years, including colorimetry, spectrometry, chemiluminescence (CL), photoelectrochemistry (PEC), and electrochemiluminescence (ECL) [ 25 , 28 , 29 ].…”

Piezoresponse in Ferroelectric Materials under Uniform Electric Field of Electrodes

“…Piezoelectric materials are an important class of materials with applications as sensors, actuators, resonators [ 1 , 2 , 3 ], electric energy harvesters [ 4 , 5 ], in various microelectronic devices [ 6 , 7 , 8 ], and in the piezoelectric catalysis for wastewater treatment [ 9 ]. Evaluating the effective piezoelectric coefficients via macroscopic response and predicting the response based on the known piezoelectric coefficients are vital in designing efficient electromechanical devices based on new materials.…”