Fabrication and Characterization of Piezoelectric Behaviors of Directionally Well-Aligned Chitosan/Glycine Biodegradable Composite Fiber Sensors

The natural polymer chitosan has gained much attention from researchers in the areas of tissue engineering and wound healing because of its biodegradability, antimicrobial activity, and piezoelectric properties, which could help improve cell growth and accelerate wound healing. Moreover, it has biocompatible and environmentally friendly properties, which are suitable for the development of sensors for medical applications. This study aims to fabricate a sensor using a natural polymer chitosan solution with glycine and nontoxic solvents as a matrix. The near-field electrospinning (NFES) technique was adopted for the preparation of well-aligned fibers. We focused on investigating the mechanical, piezoelectric, and biodegradable properties while analyzing the relationship between the process parameters and the composite solution (1–7 wt %) while adding glycine, which improves the piezoelectric properties of the composite fibers. Laser scanning confocal microscopy was used to observe the morphology of the fibers, and X-ray diffraction (XRD)/Fourier-transform infrared spectroscopy (FTIR) was also used to characterize the crystal phase and quantify the structure of the chemical material. The electrospun fibers had a consistent morphology, a high surface area-to-volume ratio, and inter/inner porosity. Finally, a uniform design and optimization tools are used to obtain the optimal spinning parameters. The piezoelectric voltage can be increased from 61.6 to 72.0 mV (∼16.9%), and the sensitivity is 2.6 mV/N. These sensors can be applied in regenerative medicine for electrical stimulation repair and preventive medicine for healthcare.