High sensitivity and flexible fabric strain sensor based on electrochemical graphene

Abstract

In this study, electrochemical graphene (ECG) was chosen to be attached to a polyester fabric with a knitted structure as a flexible fabric strain sensor through a cloth dyeing method. According to scanning electron microscopy observation and Raman scattering spectroscopy measurements, ECG was successfully attached to the fabric structure. The electromechanical performance and strain sensing properties of the graphene-based flexible strain sensor were evaluated. The resistance change and gauge factor of different ECG attached as a fabric strain sensor were quantified. The gauge factor of the fabric strain sensor with less ECG is greater than that of the fabric strain sensor with more ECG. The high gauge factor of 47 was achieved in a strain range from 0% to 2%. The fabricated strain sensor exhibited high sensitivity, fast response time and good repeatability. The fabricated ECG fabric strain sensor could be used to detect tiny physiological signals and human motion.

Magnetic Self-Assembled Pearl Necklace-like Microstructure for Improving the Performance of a Flexible Strain Sensor

“…The relative change in the resistance− strain data recorded for the films showed a monotonic increase (strain speed, 6 mm min −1 ), as shown in Figure 4a−d. These curves can be explained by eq (10). It is worth noting that these sensors have the same specifications, where A, S, and L are considered constant.…”

“…As can be seen from Figure 4b and Table 1, the GF of RDS-C increases from 1.83 to 6.38 with the mass fraction of nickel nanoparticles from 50 to 70 wt % and then decreases slightly at 72.5 to 5.72 wt % (0−180% strain), while at a small strain (0− 15% strain), the trend is opposite with a GF of 1.02 for 72.5 wt %, less than that of 50 wt %, which is 3.35 (Figure S5a (Supporting Information) and Table 1). According to eq (10), when the particle size and strain are fixed, n 0 increases with N, leading to an increase in f(n 0 ,L). That is, the overall curve should exhibit a trend where the relative resistance change increases with the mass fraction until the internal agglomeration phenomenon caused by excessive mass fraction (72.5 wt %) becomes dominant.…”

Foundry Service of CMOS MEMS Processes and the Case Study of the Flow Sensor

“…Figure 4a shows the deposition of the polysilicon above the substrate; Figure 4b represents the CMOS layer with an additional pattern of contact layer; Figure 4c depicts the standard CMOS layer with amorphous SiO2, metal M1-M6, metal 7 hard mask, and a passivation layer; Figure 4d developed the thick photoresist layer to perform the patterning; lastly, Figure 4e,f shows anisotropic silicon oxide etching and XeF2 isotropic silicon etching, respectively. The powerful CMOS MEMS foundry service in Taiwan has contributed to a variety of MEMS microsensor developments such as magnetic sensors [90,[98][99][100][101][102], humidity sensors [103][104][105][106][107][108], gas sensor [54,63,[109][110][111][112], pressure sensors [16,78,[113][114][115][116][117], thermoelectric energy harvesters [118][119][120][121][122], strain sensors [37,40,53], thermal sensors [123][124][125][126][127]<...…”

“…In the earlier stage, the CMOS MEMS process had a larger CD or minimum line width in the academic labs of Europe and USA [73][74][75][76][77][78][79][80]. As the CD kept on decreasing to 0.8 µm [35] The powerful CMOS MEMS foundry service in Taiwan has contributed to a variety of MEMS microsensor developments such as magnetic sensors [90,[98][99][100][101][102], humidity sensors [103][104][105][106][107][108], gas sensor [54,63,[109][110][111][112], pressure sensors [16,78,[113][114][115][116][117], thermoelectric energy harvesters [118][119][120][121][122], strain sensors [37,40,53], thermal sensors [123][124][125][126]…”

Ionic liquid regenerated cellulose membrane electroless plated by silver layer for ECG signal monitoring

“…Therefore the concept of dry electrodes was proposed. Most of the current dry electrodes are built on fabric, such as cotton fabric, polyester fabric, conductive silk is woven fabric, they are too heavy, which will reduce the comfort of the user (Nigusse et al 2020a; Wang et al 2021a;Xu et al 2019;Yun et al 2014). And there is a gap between the contact interface of fabric electrodes and skin, which will increase the contact impedance of the acquisition interface, thus leading to poor quality of the acquired ECG (Beckmann et al 2010;Catrysse et al 2004).…”