Enhanced Piezoelectricity in a Robust and Harmonious Multilayer Assembly of Electrospun Nanofiber Mats and Microbead-Based Electrodes

Abstract

Here, we present a simple yet highly efficient method to enhance the output performance of a piezoelectric device containing electrospun nanofiber mats. Multiple nanofiber mats were assembled together to harness larger piezoelectric sources in the as-spun fibers, thereby providing enhanced voltage and current outputs compared to those of a single-mat device. In addition to the multilayer assembly, microbead-based electrodes were integrated with the nanofiber mats to deliver a complexed compression and tension force excitation to the piezoelectric layers. A vacuum-packing process was performed to attain a tight and well-organized assembly of the device components even though the total thickness was several millimeters. The integrated piezoelectric device exhibited a maximum voltage and current of 10.4 V and 2.3 μA, respectively. Furthermore, the robust integrity of the device components could provide high-precision sensitivity to perceive small pressures down to approximately 100 Pa while retaining a linear input-output relationship.

Piezoelectric Biomaterials for Sensors and Actuators

“…Solutions to the first problem include the use of biocompatible encapsulators or fabricating lead‐free piezoelectric inorganics . For the second problem, piezoelectricity in organic polymers can be enhanced by creating composites, mixing together organic and inorganic materials, or creating multilayer piezoelectric devices . To solve the third challenge, biodegradable piezoelectric polymers can be treated under different conditions (e.g., different temperatures or stretching ratios or poling electrical fields) which will help to engineer their degradation rate …”

Hybrid lead-free polymer-based nanocomposites with improved piezoelectric response for biomedical energy-harvesting applications: A review

“…PVDF or PVDF-TrFE fibre webs, as well as other polymer nanofibres, e.g. PVDF-HFP [19] and PLLA [20,21], are typically produced by the conventional electrospinning process [17,[22][23][24]. Their higher mechanical strength results in a more robust interconnected fibre web that can maintain its structural integrity during compression and decompression.…”

“…The maximum output peak voltages measured for the harvester were 1.75, 1.29, and 0.98 V when an input force of 4 N (2 Hz) was applied at an angle of 0°, 45°, and 90°, respectively; the corresponding maximum output power values were 0.064, 0.026, and 0.02 μW, respectively. Moreover, the harvester generated a stable output voltage over 1.4×10 4 cycles, and successfully identified and converted the strain energy produced by multi-directional input forces from various human motions into electrical energy [22].…”

Fabrication of Electrospun Polymer Nanofibers with Diverse Morphologies

“…In the fields of sensing technology, optoelectronics, etc., many nanofiber mats are also assembled by using a large voltage source in the as-spun fiber to provide higher voltage and current output than a single-pad device [227]. Figure 9 shows a robust packaging method that depends on a multilayer electrospun nano-fiber mat.…”

“…( D ) Output signals of the drop test results using a small leaf, a grain of rice, and a water droplet. Reproduced from [227] with permission from the American Chemical Society; Copyright 2018.…”