Transfer-Medium-Free Nanofiber-Reinforced Graphene Film and Applications in Wearable Transparent Pressure Sensors

Abstract

Graphene exhibits properties of atomic thickness, high transparency, and high carrier mobility, which is highly desirable for a flexible transparent conductive material. However, the electronic properties of large-area chemical vapor deposition grown graphene film suffer from insulated polymer contaminations introduced by the transfer process and the easily cracked nature. Here, we report a preparation method of a transfermedium-free large-area nanofiber-reinforced graphene (a-PAN/G) film simply by annealing the electrostatically spun polyacrylonitrile (PAN) nanofibers on the graphene film. The film could be free-standing on water and suspended in air with high transparency and enhanced electrical and mechanical properties compared to that of a monolayer graphene film. The flexible transparent a-PAN/G films were demonstrated as active materials for sensitive pressure sensors. The obtained pressure sensors demonstrate high sensitivity (44.5 kPa −1 within 1.2 kPa), low operating voltage (0.01−0.5 V), and excellent stability for 5500 loading− unloading cycles, revealing promising potential applications in wearable electronics.

Reversible Crumpling of 2D Titanium Carbide (MXene) Nanocoatings for Stretchable Electromagnetic Shielding and Wearable Wireless Communication

“…2.0 µm) were highly entangled within the stacked MXene nanosheets (dimension ca. 0.2 × 0.5 µm) and formed strong bridges, which largely reinforced the resulting S‐MXene coating …”

Interfacial Phenomena of Advanced Composite Materials toward Wearable Platforms for Biological and Environmental Monitoring Sensors, Armor, and Soft Robotics

“…An additional fabricated sensor uses a similar flexible design using polymers for durability. Ren et al designed a flexible, transparent sensor relying on a nanofiber reinforced graphene film with high mechanical strength (Young's modulus of 747.9 ± 77.6 GPa without annealed polyacrylonitrile fibers, and 1.07 ± 0.08 TPa with the annealed fibers) and conductivity. The piezoresistive properties of the sensor exploit the conductivity of the annealed polyacrylonitrile (PAN) fibers on graphene film as deformation occurs within PAN fiber/graphene and polydimethylsiloxane (PDMS) layers.…”

“…The interface for biophysical sensors is of extreme importance, as the relationship between the materials determines the type of response that will occur. Most biophysical sensors function based off of measuring the response of the platform electrically, either measuring relative resistance change or less commonly, current and voltage . A recent platform design for monitoring strain is the incorporation of a conductive material, such as a gold nanoparticle coating, deposited on top of a flexible and porous substrate, such as polyurethane foam .…”

“…These correspond to the major sections of this review, including biomonitoring sensors for biophysical detection, bioanalyte sensors for detection of biomarkers, environmental sensors for personal pollutant monitoring, haptics for pressure sensing, soft robotics for human–electronic interfacing, and armor with enhanced safeguarding. i) Adapted with permission . Copyright 2019, American Chemical Society.…”

Multiple-Jet Needleless Electrospinning Approach via a Linear Flume Spinneret

“…Compared with traditional fibers, nanofibers exhibit many advantages, such as high specific surface area, high porosity and controllable nanofiber diameter [1]. Nanofibers have been widely applied in many fields, such as filtration materials [2,3], sensor [4], tissue engineering scaffolds [5,6], sensors [7] and energy storage materials [8]. It is common knowledge that electrospinning is a simple and convenient method to prepare nanofibers.…”