Browsing by Subject "piezoelectricity"

Now showing 1 - 5 of 5

Access status: Open Access ,
Enhanced Electroactive Phases of Poly(vinylidene Fluoride) Fibers for Tissue Engineering Applications
(2024) Zaszczyńska, Angelika; Gradys, Arkadiusz; Ziemiecka, Anna; Szewczyk, Piotr K.; Tymkiewicz, Ryszard; Lewandowska-Szumieł, Małgorzata; Stachewicz, Urszula; Sajkiewicz, Paweł
Wydział Inżynierii Metali i Informatyki Przemysłowej
Nanofibrous materials generated through electrospinning have gained significant attention in tissue regeneration, particularly in the domain of bone reconstruction. There is high interest in designing a material resembling bone tissue, and many scientists are trying to create materials applicable to bone tissue engineering with piezoelectricity similar to bone. One of the prospective candidates is highly piezoelectric poly(vinylidene fluoride) (PVDF), which was used for fibrous scaffold formation by electrospinning. In this study, we focused on the effect of PVDF molecular weight (180,000 g/mol and 530,000 g/mol) and process parameters, such as the rotational speed of the collector, applied voltage, and solution flow rate on the properties of the final scaffold. Fourier Transform Infrared Spectroscopy allows for determining the effect of molecular weight and processing parameters on the content of the electroactive phases. It can be concluded that the higher molecular weight of the PVDF and higher collector rotational speed increase nanofibers’ diameter, electroactive phase content, and piezoelectric coefficient. Various electrospinning parameters showed changes in electroactive phase content with the maximum at the applied voltage of 22 kV and flow rate of 0.8 mL/h. Moreover, the cytocompatibility of the scaffolds was confirmed in the culture of human adipose-derived stromal cells with known potential for osteogenic differentiation. Based on the results obtained, it can be concluded that PVDF scaffolds may be taken into account as a tool in bone tissue engineering and are worth further investigation.
Access status: Open Access ,
Flint and fire
(2014) Pawlikowski, Maciej
Various knapping techniques of flints used at Stone Age effected production of various implements but was reason of discovery of lightning striking i.e. creation of way kindle of fire. An article presents results of investigation of flints and relations: age of flints, crystallinity of flints – piezoelectricity, age of flints-piezoelectricity.
Access status: Open Access ,
Hybrid piezo-, pyro-, and triboelectric nanogenerator based on PVDF and rGO composite fibers for a multifunctional approach to energy harvesting applications
(2025) Sukumaran, Sunija; Szewczyk, Piotr K.; Bajda, Tomasz; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki Przemysłowej
Recently, wearable nanogenerators have gained interest in energy harvesting and sensors, driven by smart electronics and Internet of Things (IoT) advancements. Here, we have developed a multifunctional nanogenerator that can convert mechanical and thermal energy into electrical energy via piezoelectric, triboelectric, and pyroelectric effects. The electrospun nanogenerator was fabricated to investigate the effect of reduced graphene oxide (rGO) on the energy generation of polyvinylidene fluoride (PVDF) fibers. The highest amount of electroactive β phase (81 %) and crystallinity (48.58 %) were obtained for 7 wt% rGO/PVDF fiber composite. Then, the 7 wt% rGO/PVDF composite was taken to prepare the piezo, tribo, and pyroelectric nanogenerator, and characterized using piezoresponse force microscopy (PFM), Kelvin probe microscopy (KPFM), and scanning thermal microscopy (SThM). Furthermore, the nanogenerator was made using the composite mat, illustrating its potential for powering small electronic devices using piezoelectric power and an enormous triboelectric power density of 3.37 ± 0.72 mWcm−2. We also demonstrate the device’s multifunctionality under thermal fluctuations. The results show the synergetic tribo and pyroelectric current of 33nA from 7 wt% rGO/PVDF. The present work indicates the significance of rGO inclusion into a PVDF matrix, resulting in enhanced multifunctional properties for energy harvesting, thereby enabling self-powering capabilities for microelectronic devices.
Access status: Open Access ,
Krzemień i ogień
(2014) Pawlikowski, Maciej
Obróbka krzemieni metodą odłupkową, którą stosowano w Epoce Kamienia pozwalała nie tylko wytwarzać użyteczne przedmioty, ale spowodowała odkrycie efektu krzesania iskier, którego skutkiem było odkrycie sposobu wzniecania ognia. Ten wielki wynalazek spowodował technologiczny i cywilizacyjny skok Ludzkości. Bez odłupkowych technik obróbki kamienia i bez krzemieni nie umielibyśmy wskrzeszać i rozpalać ognia. Praca prezentuje wyniki badań relacji miedzy strukturą krzemieni, ich wiekiem oraz właściwościami piezoelektrycznymi, a możliwością krzesania iskier i ognia.
Access status: Open Access ,
Optimizing Piezoelectric Coefficient in PVDF Fibers: Key Strategies for Energy Harvesting and Smart Textiles
(2023) Sukumaran, Sunija; Szewczyk, Piotr K.; Knapczyk-Korczak, Joanna; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki Przemysłowej
With the advancement in smart electronic devices and self-powered devices, the demand for piezoelectric polymers found potential research interest. Among these, electrospun polyvinylidene fluoride (PVDF) fibers have gained attention for energy harvesting due to their flexibility and higher piezoelectric coefficient. We compare various methods to enhance PVDF's piezoelectric properties, including different solvents (DMAc, DMF), conductive filler (rGO), and annealing as post-treatment. Our results indicate that PVDF/rGO fibers in DMAc solvent exhibit the highest β phase fraction and crystallinity. Moreover, for the first time, we present the piezoelectric properties of PVDF/rGO electrospun single fiber using high voltage switching spectroscopy piezoelectric force microscopy (HVSS-PFM). The highest piezoelectric coefficient (d33) was measured for PVDF/DMAc-rGO composite fibers. Notably, PVDF/rGO in DMAc solvent significantly improves the piezoelectric coefficient, leading to a remarkable fourfold increase in power density compared to pure PVDF, making it a promising material for energy harvesting applications.