Conjugated Polymer-Based Nanocomposites for Pressure Sensors

Abstract

Flexible sensors are the essential foundations of pressure sensing, microcomputer sensing systems, and wearable devices. The flexible tactile sensor can sense stimuli by converting external forces into electrical signals. The electrical signals are transmitted to a computer processing system for analysis, realizing real-time health monitoring and human motion detection. According to the working mechanism, tactile sensors are mainly divided into four types—piezoresistive, capacitive, piezoelectric, and triboelectric tactile sensors. Conventional silicon-based tactile sensors are often inadequate for flexible electronics due to their limited mechanical flexibility. In comparison, polymeric nanocomposites are flexible and stretchable, which makes them excellent candidates for flexible and wearable tactile sensors. Among the promising polymers, conjugated polymers (CPs), due to their unique chemical structures and electronic properties that contribute to their high electrical and mechanical conductivity, show great potential for flexible sensors and wearable devices. In this paper, we first introduce the parameters of pressure sensors. Then, we describe the operating principles of resistive, capacitive, piezoelectric, and triboelectric sensors, and review the pressure sensors based on conjugated polymer nanocomposites that were reported in recent years. After that, we introduce the performance characteristics of flexible sensors, regarding their applications in healthcare, human motion monitoring, electronic skin, wearable devices, and artificial intelligence. In addition, we summarize and compare the performances of conjugated polymer nanocomposite-based pressure sensors that were reported in recent years. Finally, we summarize the challenges and future directions of conjugated polymer nanocomposite-based sensors.

Polymer ionogels and their application in flexible ionic devices

“…88,89 Moreover, by mimicking human skin, ITSs aim to achieve higher sensitivity and a broader pressure response range. 90 In recent years, significant advancements have been made in the development of ITSs, and the resulting ionic skin can be utilized in applications such as human health monitoring, humanmachine interaction, and the internet of things, 75,[91][92][93] and so forth. Based on different transduction mechanisms, ITSs can be classified into three types: resistive, 94 capacitive, 95 and piezoelectric.…”

“…Therefore, ITSs exhibit remarkable biocompatibility and hold great potential for emerging technologies, including wearable and bio‐inspired sensor platforms 88,89 . Moreover, by mimicking human skin, ITSs aim to achieve higher sensitivity and a broader pressure response range 90 . In recent years, significant advancements have been made in the development of ITSs, and the resulting ionic skin can be utilized in applications such as human health monitoring, human‐machine interaction, and the internet of things, 75,91–93 and so forth.…”

Spatial Calibration of Humanoid Robot Flexible Tactile Skin for Human–Robot Interaction

“…The flexibility is particularly appreciated as it allows the sensors to be wrapped on most of the surfaces of the robot or the device it is integrated on [14,17]. This property enables the use of these sensors in several application fields, including health monitoring, medical diagnosis, artificial intelligence, and electronic skin for robots or enhanced humans [13,18].…”

“…The recent progress in flexible tactile skins includes the creation of ultrathin sensors with good sensing capabilities [19], the use of new materials such as conjugated polymers [18] or Parylene MEMS [20], the use of new sensing modalities as electrical impedance tomography [17], the development of skins with damage detection capabilities [21], the reproduction of complex human-like sensing imitating the fingertips [20], integration on robots [16], and combined use with artificial intelligence methods as deep learning [22]. As we can see, progress is made on both materials side and application side, including robotics applications.…”

Multifunctional Polymeric Nanocomposites for Sensing Applications—Design, Features, and Technical Advancements

“…The chemical structure of nanomaterials greatly influences sensing properties [2,3]. In the case of polymer nanocomposites, a range of polymers from the categories of conducting polymers, thermoplastics, elastomers, etc., have been used [4][5][6]. Among all polymers, conducting or conjugated polymers have been found effective to be utilized to design competent nanocomposite sensors [7,8].…”