Metal-Free Multilayer Hybrid PENG Based on Soft Electrospun/-Sprayed Membranes with Cardanol Additive for Harvesting Energy from Surgical Face Masks

Abstract

Disposable surgical face masks are usually used by medical/nurse staff but the current Covid-19 pandemic has caused their massive use by many people. Being worn closely attached to the people’s face, they are continuously subjected to routine movements, i.e., facial expressions, breathing, and talking. These motional forces represent an unusual source of wasted mechanical energy that can be rather harvested by electromechanical transducers and exploited to power mask-integrated sensors. Typically, piezoelectric and triboelectric nanogenerators are exploited to this aim; however, most of the current devices are too thick or wide, not really conformable, and affected by humidity, which make them hardly embeddable in a mask, in contact with skin. Different from recent attempts to fabricate smart energy-harvesting cloth masks, in this work, a wearable energy harvester is rather enclosed in the mask and can be reused and not disposed. The device is a metal-free hybrid piezoelectric nanogenerator (hPENG) based on soft biocompatible materials. In particular, poly­(vinylidene fluoride) (PVDF) membranes in the pure form and with a biobased plasticizer (cardanol oil, CA) are electrospun onto a laser-ablated polyimide flexible substrate attached on a skin-conformable elastomeric blend of poly­(dimethylsiloxane) (PDMS) and Ecoflex. The multilayer structure of the device harnesses the piezoelectricity of the PVDF nanofibers and the friction triboelectric effects. The ultrasensitive mechanoelectrical transduction properties of the composite device are determined by the strong electrostatic behavior of the membranes and the plasticization effect of cardanol. In addition, encapsulation based on PVDF, PDMS, CA, and parylene C is used, allowing the hPENG to exhibit optimal reliability and resistance against the wet and warm atmosphere around the face mask. The proposed device reveals potential applications for the future development of smart masks with coupled energy-harvesting devices, allowing to use them not only for anti-infective protection but also to supply sensors or active antibacterial/viral devices.

State-of-the-art review of advanced electrospun nanofiber yarn-based textiles for biomedical applications

“…Some polymers with tribo/piezoelectric characteristics, such as PVDF, PVDF-TrFE, and PVDF-HFP, can be fabricated into electrospinning-based NYs and further constructed into textile-shaped filter layers for face mask application [ 231 , 232 ]. The tribo/piezoelectric nanotextile filter layer can generate electrical charges during the breathing process, which can produce strong electrostatic attraction to effectively block the virus-containing aerosols [ 233 , 234 ]. The schematic and filtration mechanisms of the reusable tribo/piezoelectric nanotextile-based face masks is shown in Fig.…”

Nanotechnology Transition Roadmap toward Multifunctional Stimuli-Responsive Face Masks

“…The ability to decontaminate the face mask structure without reducing the filter performance and stability opens the door to the development of long-term reusable and safe PPE . In addition, nanotechnology-based strategies endow filter membranes with novel unique features, thus opening the field to brand-new devices such as energy-harvesting face masks with self-powered properties …”

Ultraviolet and Infrared Irradiations Sensing of Gel-Orange Dye Composite-Based Flexible Electrochemical Cells

“…The sensing structure was mainly based on platinum electrodes and a ferroelectric (strontium bismuth tantalate) layer. A soft biocompatible material-based piezoelectric nanogenerator as a non-disposable and reusable energy harvester was fabricated, which can be used by enclosing it in the mask [ 18 ]. These nanogenerators are mainly based on electrospun membranes of pure PVDF poly(vinylidene fluoride) and PVDF with cardanol oil on a flexible laser-ablated polyimide substrate.…”