A capacitive sensor using resin thermoplastic elastomer and carbon fibers for monitoring pressure distribution

Thuy

et al. 2022

Adv Funct Materials

Synergistically enhancing luminescent and ferroelectric (SELF) properties are observed from a tetraphenylethene (TP) substituted with clipping groups (C), where the C is consisting of a 4-[3,5-bis-(3-decyloxy-styryl)-styryl]-phenyl (DOS) unit. The DOS units of TPCn are self-assembled via intermolecular interaction to clip themselves and induce TP aggregation, as evidenced by clip-induced quenching of emission at DOS units (E clip ) accompanied by aggregation-induced emission enhancement of TPs (E AIE ). TPC4 demonstrates strong photoluminescence in a dilute chloroform solution and large E AIE in aqueous (>50%) THF solution. TPCn demonstrates SELF properties in film state, with high quantum yields of photoluminescence (>80%) and ferroelectric switching. Due to the introduction of four clips, TPC4 has a higher remnant polarization (P r = 2.27 µC cm −2 ) at room temperature than TPC1. TPC4 is successfully employed in a light-emitting electrochemical cell to achieve over 1290 cd m −2 under pulsed current conditions. The TPC4 film on a flexible substrate produced a piezoelectric output voltage of up to 0.13 V and a current density of 1.14 nA cm −2 upon bending. These results indicate that the side chain clipping and TP aggregation resulted in unprecedented flexible SELF properties in a single compound, offering simultaneous enhancement of electroluminescence, mechanical sensitivity, and energy harvesting capacity.

Section: Aiee Property and Molecular Packing Structuresupporting

confidence: 83%

Section: Aiee Property and Molecular Packing Structuresupporting

confidence: 83%

Synergistic Enhancement of Luminescent and Ferroelectric Properties through Multi‐Clipping of Tetraphenylethenes

Thuy

et al. 2022

Adv Funct Materials

ACS Appl. Polym. Mater.

“…Regarding the resistive sensors, TPU is combined with conductive materials to form the sensing component in which changes in resistivity can be observed by the application of external stress. Capacitive sensors, on the other hand, consist of two electrodes accompanied by a dielectric entity in the middle. , Noteworthy, due to the higher sensitivity and adjustable dielectric constant, TPU-based composites have the capability to serve as a stretchable electrode or dielectric composite in this type of sensor. Introduction of conductive entities into TPU-based strain sensors endows TPU with electrical conductivity, and, in turn, the TPU renders conductive materials with excellent ductility and stretchability .…”

Section: The Role Of Conductive Materials In Tpu-based Sensorsmentioning

confidence: 99%

Recent Advances of Flexible Strain Sensors Based on Conductive Fillers and Thermoplastic Polyurethane Matrixes

Chen

Xie

Wang

et al. 2021

Self Cite

Over recent years, flexible strain sensors have been playing an increasingly important role, especially in wearable electronics, healthcare equipment, electronic skins (e-skins), and soft robots. Numerous materials are utilized in these applications; however, thermoplastic polyurethane (TPU) is prominently used for its elastomer-like behavior, suitable flexibility, and facility of combination with diverse conductive materials. These characteristics satisfy the growing demands for better stretchability, higher sensitivity, and a wider workable sensing range of flexible strain sensors. In this review paper, recent progress on TPU-based strain sensors is tracked and discussed, including carbonaceous entities, silver nanomaterials, and conductive polymers in terms of various conductive materials first. Afterward, exciting and effective designing of macro- and microstructures, as well as their influence on the performance of strain sensors, is discussed. Finally, TPU-based strain sensors’ wide applications and distinctive multifunctionality are presented and reviewed. This review paper presents the profound significance and attractive prospects of TPU-based flexible strain sensors in the design and development of intelligent devices.

“…Conventional flexible capacitive sensors consist of a parallel‐plate capacitor, which comprises two conformable electrodes with a dielectric layer in‐between, [ 62–64 ] as presented in Figure . Stretchable dielectric materials are commonly used as flexible supports for soft strain sensors, such as rubbers (e.g., natural rubber and thermoplastic elastomers (TPEs)) [ 65–71 ] and silicone‐based elastomers (e.g., Ecoflex, Dragon Skin, and polydimethylsiloxane (PDMS)). [ 72–80 ] A huge difference in Young modulus between the thin metallic film (gold, aluminum, and platinum) and flexible elastomer or rubber causes cracks and buckling under stretching.…”

Section: Mechanisms and Sensitivitymentioning

confidence: 99%

Strain Sensing by Electrical Capacitive Variation: From Stretchable Materials to Electronic Interfaces

Nesser

Lubineau

2021

Adv Elect Materials

Sensing the motion of objects and humans is essential for various applications, including human‐machine interfaces. Over the past few years, motion sensing has been extensively studied using capacitive strain sensors that can be utilized for wireless communications. The performance and functionality of capacitive strain sensors have been improved by achieving high sensitivity, large‐area sensing, ultra‐stretchability, and simplicity in design, measurement methods, and wireless integration. This review article highlights recent developments in capacitive strain sensors, including their characteristics and applications. First, the mechanisms and techniques employed to enhance the sensitivity of capacitive strain sensors are reviewed. Then, the notable features of this sensing strategy are highlighted, such as its ability to cover a wide area, properties of the required electronic interface, and sensor implementation inside a remote measurement system via an oscillating circuit. Therefore, a global review of the capacitive strain sensor that has been previously attempted can participate in developing an effective sensing method to meet the market need.