In portable electronics, self-powered biodegradable electrical equipment that monitors important biological indicators of the nervous system is in high demand. The development and application of a PDMS/PPy polymerized film-based piezoelectric nanogenerator as a self-powered vascular blood pressure gauge is the subject of a recent study available as a pre-proof in the journal Materials Research Bulletin.
Study: Lead-free PDMS/PPy based low-cost wearable piezoelectric nanogenerator for self-powered pulse pressure sensor application. Image Credit: Login/Shutterstock.com
The crystal structure alignment and chemical properties of nanocomposite polymers are confirmed by X-ray diffraction and Raman investigations. Results suggest that using a biodegradable nanogenerator as a pressure sensor has a lot of promise for constructing self-powered devices for biomedical applications.
Importance of Piezoelectric Nanogenerators
Increased energy demands have worsened the energy crisis. As a result, new forms of renewable energy are being investigated to reduce the reliance on non-renewable resources such as coal and fossil fuels.
Piezoelectric nanogenerators have developed in recent decades as viable prospects for addressing the energy problem as they can convert waste physical energy in the form of physiological vibrations, tidal currents, sound waves, and wind speed into energy sources.
Limitations of Inorganic Piezoelectric Materials
Inorganic materials' higher dielectric charging efficiency aids in the development of high-performance piezoelectric power sources. Nanogenerators have been made on a range of surfaces, including silicon, copper, and aluminum.
Chemical vapor deposition, laser ablation, and atomic layer deposition are all costly and complicated clean-room processes for depositing inorganic piezoelectric crystals on these platforms.
Piezoelectric nanogenerators made with these substances are typically rigid, restricting their utility in portable and adaptable devices. As a result, organic substances are being investigated as a means of developing a bendable, extremely sensitive, and long-lasting piezoelectric nanogenerator.
Polypyrrole (PPy): A Highly Conductive Polymer Material
Polypyrrole (PPy) is a conducting material polymer that can be blended readily with other materials to make composites and has a straightforward synthesis procedure.
PPy has traditionally been employed in a variety of technologies, including superconductors, photodiodes, and electromagnetic shielding.
According to recent research, the addition of PPy nanoparticles increases the dielectric properties and conductance of the PDMS/Ppy composite, resulting in the creation of numerous interfacial polarization patterns. Furthermore, because of better interface compliance, organic PPy may significantly minimize interfacial flaws. As a result, charge could easily travel through the composite films, allowing nanogenerators to improve their electrical output efficiency.
The non-centrosymmetric structure of the -PPy material in the PDMS/PPy polymeric network produces a piezoelectric effect. Nano-dipoles occur inside the PDMS/PPy piezoelectric nanocomposites when external pressure is applied.
When force is exerted to the generated nano-dipoles, positive charges are induced on one side of the nanogenerator, and equivalent and opposite negatively charged electrons are created on the other side, making it appropriate for nanogenerator purposes.
A Novel PDMS/PPy based Piezoelectric Nanogenerator
In this work, a unique PDMS/PPy based piezoelectric nanogenerator was produced using a minimal-cost spin coating process. Because of its excellent sensitivity to small pressures, PDMS/PPy composite polymer was employed as a piezoelectric electrode layer.
A piezoelectric film of PDMS/PPy complex material was synthesized on the ITO-coated PET platform and an aluminum thin film deposited over a PET surface was used as a reference electrode because of its high conductivity and adaptability
Research Findings and Conclusion
To conclude, the researchers successfully developed a highly responsive and adaptable piezoelectric nanogenerator relying on PDMS/PPy. The additive impact of PDMS and the PPy polymer's a-β’ stage copolymer chain results in a 12 V resultant voltage and a high current concentration.
Considering its output voltage of 12 V, the constructed nanogenerator is employed to determine radial artery pulses and may also be used to power a variety of portable nanoelectronics clinical imaging applications.
The resultant voltage and current intensity rise as the percentage of PPy within the PDMS material rises. Due to the nanogenerator's exceptional responsiveness, it was utilized to determine arterial pressure.
The development of arterial blood rate using a PDMS/PPy-based nanogenerator paves the way for the development of adaptable smart sensing gadgets for application in point-of-care medical diagnostics.
Veeralingam, S. et al. (2022). Lead-free PDMS/PPy based low-cost wearable piezoelectric nanogenerator for self-powered pulse pressure sensor application. Materials Research Bulletin. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0025540822000897