Bi₂S₃/PVDF/Ppy-Based Freestanding, Wearable, Transient Nanomembrane for Ultrasensitive Pressure, Strain, and Temperature Sensing

Abstract

Flexible nanofiber-based composites have been widely explored because of their light weight, high surface area, scalability, and tunable physical and mechanical properties. In this work, we report electrospun 2D-Bi2S3 incorporated PVDF/PPy nanofibers as a versatile platform for ultrasensitive pressure, strain, and temperature sensing. Detailed characterization studies revealed the formation of ultrathin nanofibers and characteristic Raman and IR vibration modes of PPy, 2D-Bi2S3, β-phased PVDF. The fabricated pressure sensor exhibited a sensitivity of 1.51 kPa–1 in the wide linear range of 1–50 kPa and a response time of 0.04 s. The practical ability of pressure sensor was tested by successfully detecting pulse rate of human radial arteries. Further, the BS- PVDF/PPy composite was employed as a strain sensor in the range of 3.1–61.5%, displayed a gauge factor (GF) of 45.45 and a response time of 0.1 s. The wearable sensor was capable of detecting minute changes in hand gestures by recognizing the microstrains applied to the device. The sensing mechanism can be attributed to the excellent piezoelectric property of β- phase PVDF, electron transport property of PPy nanoparticles and tensile strength of the BS nanoparticles embedded in the polymer matrix. When used as a wearable temperature sensor, the versatile device demonstrated a linear range of detection 24- 48 °C with a response time of 0.33 s and Temperature coefficient of resistance (TCR) of −0.1117 °C–1 that can be attributed to the phonon-assisted hoping mechanism. The nanofiber composite dissolved in volatile organic solvent acetone in 5 days with the least impact on the surrounding environment thus making this a promising strategy to develop transient technologies aimed at zero-waste, green electronics.

Interface Induced High-Performance Piezoelectric Nanogenerator Based on a Electrospun Three-Phase Composite Nanofiber for Wearable Applications

“…Again the pure polymer-based PENGs lack far behind the ceramic-based PENGs in terms of piezoresponse. In the past decade, polymer–ceramic composites have been studied widely as those exhibit comparatively higher piezoresponse than pure polymers along with flexibility. , Poly­(vinylidene fluoride) (PVDF) is preferred as the matrix material in piezoceramic based composites very widely due to its nontoxicity, good chemical resistance, thermal stability, and flexibility, and the most important is that PVDF itself shows piezoelectricity in its electroactive β-phase . In the β-phase, PVDF possesses all trans (−TTTT−) planar zigzag structure, in which the effective dipole moment perpendicular to the carbon backbone is caused by the summation of dipole moments of C–F and C–H bonds .…”

Bi2S3@MoS2 Nanoflowers on Cellulose Fibers Combined with Octahedral CeO2 for Dual-Mode Microfluidic Paper-Based MiRNA-141 Sensors

“…The color-developing channel and ruler printed by inkjet printing technology can be used to intuitively determine the flow distance of the color-developing fluid without distinguishing the color depth of the color-developing product, which greatly improves the accuracy and portability of the color-developing reaction. In addition, to improve the sensitivity of electrochemical detection, nanomaterials with high catalytic activity and good biocompatibility are introduced on the μPAD as signal amplification probes. , To obtain functionalized μPAD, metallic sulfide has been chosen to be in situ grown onto the surface of paper fibers due to its unique electrical, catalytic, and mechanical properties enabled by the high surface volume ratio and small size. − Bi 2 S 3 , as a representative metallic sulfide, can directly increase the transmission speed of electrons and obtain amplified electrochemical signals without other redox molecules, thereby significantly improving the performance of electrochemical analysis . Similarly, MoS 2 , as a transition metal sulfide, has been widely used in catalyzing reduction of H 2 O 2 on account of its excellent thermal stability, good biocompatibility, and high electrocatalytic activity .…”

A Fully Flexible Intelligent Thermal Touch Panel Based on Intrinsically Plastic Ag2S Semiconductor

“…Our Ag 2 S‐based flexible sensor shows extraordinarily high‐performance, superior to the other reported flexible temperature sensors in literatures (see Table S1, Supporting Information). [ 14,17,30–38 ]…”