A Fast-Response Electroactive Actuator Based on TEMPO-Oxidized Cellulose Nanofibers

2021 ◽  
Author(s):  
Yan Huang ◽  
Fang Wang ◽  
Liying Qian ◽  
Xiuhua Cao ◽  
Beihai He ◽  
...  
Keyword(s):  
Layered Structure ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Low Voltage ◽  
Cellulose Nanofibers ◽  
Conductive Polymer ◽  
Fast Response ◽  
Tempo Oxidation ◽  
Ion Migration ◽  
High Mechanical Strength

Abstract Cellulose-based electroactive actuators are promising candidates for biomimetic robots and biomedical applications due to their lightweight, high mechanical strength, and natural abundance. However, cellulose-based electroactive actuators exhibit lower actuation performance than traditional conductive polymer actuators. This work reports a fast-response cellulose-based electroactive actuator based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized nanocellulose (TOCNF) film with layered structure fabricated by evaporation, and gold electrodes prepared by ion sputtering. The residual ions during the TEMPO oxidation process and the layered structure due to self-assembly accelerate the ion migration efficiency in actuators. The proposed actuator can reach a tip displacement of 32.1 mm at a voltage of 10 V and deflect 60° in 5 s. After applying a reverse 10 V voltage, the actuator can also be quickly deflected (42.5 mm). In addition, the actuator also shows high electrical actuation performance at low voltage (5 V). The excellent electroactive performance of as-prepared TOCNF/Au enables the feasibility to be applied to actuators.

scholarly journals Self-assembly formation of the layered structure of conductive polymer blend film based on phase separation phenomena

2006 ◽  
Vol 62 (2) ◽  
pp. 29-33
Author(s):  
Naidi Tan ◽  
Noriko Asano ◽  
Katsuo Orihara ◽  
Rikiya Sato ◽  
Seiji Hirose ◽  
...  
Keyword(s):  
Phase Separation ◽  
Polymer Blend ◽  
Layered Structure ◽  
Self Assembly ◽  
Conductive Polymer ◽  
Blend Film ◽  
Polymer Blend Film

Chitosan/Polyethylene Oxide (PEO) Filled Carbonized Wood Fiber Conductive Composite Film

2020 ◽  
Vol 1010 ◽  
pp. 638-644
Author(s):  
Mohd Pisal Mohd Hanif ◽  
Abd Jalil Jalilah ◽  
Mohd Fadzil Hanim Anisah ◽  
Arumugam Tilagavathy
Keyword(s):  
Electrical Conductivity ◽  
Tensile Strength ◽  
Polyethylene Oxide ◽  
Biomedical Applications ◽  
Wood Fiber ◽  
Conductive Polymer ◽  
Renewable Resource ◽  
Blend Films ◽  
Conductive Composite Film ◽  
Carbonized Wood

Biopolymer-based conductive polymer composites (CPCs) would open up various possibilities in biomedical applications owing to ease of processing, renewable resource and environmentally friendly. However, low mechanical properties are a major issue for their applications. In this study, the investigated the conductivity of chitosan/ PEO blend films filled with carbonized wood fiber (CWF) prepared by solution casting. The effect of CWF was also investigated on tensile properties and their morphological surfaces. The tensile results from different ratios of chitosan/PEO blend films without CWF show that the tensile strength and modulus increased with the increase of chitosan content and chitosan/PEO blend film with 70/30 ratio exhibited the best combination of tensile strength and flexibility. However, a reduction of tensile strength was observed when CWF amount was increased while the modulus of the tensile shows an increment. The film also exhibited higher electrical conductivity as compared to low chitosan ratio. The addition of CWF greatly enhanced the conductivity three-fold from 10-10 to 10-6 S/cm. The electrical conductivity continued to increase with the increase of CWF up to 30wt%. The surface morphology by Scanning Electron Microscopy (SEM) exhibits the absence of phase separation for the blends indicating good miscibility between the PEO and chitosan. Incorporation of CWF into the blend films at 5wt% showed agglomeration. However, the increase of CWF created larger agglomerations that formed conductive pathways resulting in improved conductivity. FTIR analysis suggested that intermolecular interactions occurred between chitosan and PEO while CWF interacts more with the protons of PEO.

scholarly journals The effects of cononsolvents on the synthesis of responsive particles via polymerisation-induced thermal self-assembly

2021 ◽  
Author(s):  
Marissa Morales-Moctezuma ◽  
Sebastian G Spain
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Self Assembly ◽  
Biomedical Applications

Nanogels have emerged as innovative platforms for numerous biomedical applications including gene and drug delivery, biosensors, imaging, and tissue engineering. Polymerisation-induced thermal self-assembly (PITSA) has been shown to be suitable...

scholarly journals Alcohol-based highly conductive polymer for conformal nanocoatings on hydrophobic surfaces toward a highly sensitive and stable pressure sensor

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jung Joon Lee ◽  
Srinivas Gandla ◽  
Byeongjae Lim ◽  
Sunju Kang ◽  
Sunyoung Kim ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Mechanical Stability ◽  
Exchange Process ◽  
Conductive Polymer ◽  
High Sensitivity ◽  
Fast Response ◽  
Pdms Surface ◽  
Practical Applications ◽  
Sensor Applications ◽  
Water Based

Abstract Conformal and ultrathin coating of highly conductive PEDOT:PSS on hydrophobic uneven surfaces is essential for resistive-based pressure sensor applications. For this purpose, a water-based poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) solution was successfully exchanged to an organic solvent-based PEDOT:PSS solution without any aggregation or reduction in conductivity using the ultrafiltration method. Among various solvents, the ethanol (EtOH) solvent-exchanged PEDOT:PSS solution exhibited a contact angle of 34.67°, which is much lower than the value of 96.94° for the water-based PEDOT:PSS solution. The optimized EtOH-based PEDOT:PSS solution exhibited conformal and uniform coating, with ultrathin nanocoated films obtained on a hydrophobic pyramid polydimethylsiloxane (PDMS) surface. The fabricated pressure sensor showed high performances, such as high sensitivity (−21 kPa−1 in the low pressure regime up to 100 Pa), mechanical stability (over 10,000 cycles without any failure or cracks) and a fast response time (90 ms). Finally, the proposed pressure sensor was successfully demonstrated as a human blood pulse rate sensor and a spatial pressure sensor array for practical applications. The solvent exchange process using ultrafiltration for these applications can be utilized as a universal technique for improving the coating property (wettability) of conducting polymers as well as various other materials.

Simulated Clustering Dynamics of Colloidal Magnetic Nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Frederik Laust Durhuus ◽  
Lau Halkier Wandall ◽  
Mathias Hoeg Boisen ◽  
Mathias Kure ◽  
Marco Beleggia ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Magnetic Nanoparticle ◽  
Bottom Up ◽  
Novel Materials ◽  
Nanoparticle Clusters ◽  
Clustering Dynamics

Magnetically guided self-assembly of nanoparticles is a promising bottom-up method to fabricate novel materials and superstructures, such as, for example, magnetic nanoparticle clusters for biomedical applications. The existence of assembled...

scholarly journals Layer-by-Layer Self-Assembly Composite Coatings for Improved Corrosion and Wear Resistance of Mg Alloy for Biomedical Applications

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 515
Author(s):  
Tongfang Liu ◽  
Song Rui ◽  
Sheng Li
Keyword(s):  
Wear Resistance ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Composite Coatings ◽  
Covalent Bond ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Layer By Layer ◽  
Corrosion Propagation ◽  
Chemical Linkage

Mg alloys are promising biomedical metal due to their natural degradability, good processability, and favorable mechanical properties. However, the poor corrosion resistance limits their further clinical applications. In this study, the combined strategies of surface chemical treatment and layer-by-layer self-assembly were used to prepare composite coatings on Mg alloys to improve the biocorrosion resistance. Specially, alkalized AZ91 Mg alloy generated chemical linkage with silane via Si–O–Mg covalent bond at the interface. Subsequently, Si–OH group from silane formed a crosslinked silane layer by Si–O–Si network. Further chemical assembly with graphene oxide (GO), lengthened the diffusion pathway of corrosive medium. The chemically assembled composite coatings could firmly bond to Mg alloy substrate, which persistently and effectively acted as compact barriers against corrosion propagation. Improved biocorrosion resistance of AZ91 Mg alloy with self-assembly composite coatings of silane/GO was subsequently confirmed by immersion tests. Besides, the Mg alloy exhibited good wear resistance due to outside layer of GO with a lubricant effect. Cell viability of higher than 75% had also been found for the alloy with self-assembly composite coatings, which showed good cytocompatibility.

scholarly journals A New Hope: Self-Assembling Peptides with Antimicrobial Activity

Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 166 ◽  
Author(s):  
Lucia Lombardi ◽  
Annarita Falanga ◽  
Valentina Del Genio ◽  
Stefania Galdiero
Keyword(s):  
Self Assembly ◽  
Biomedical Applications ◽  
High Specificity ◽  
Antibacterial Activities ◽  
Mechanisms Of Action ◽  
Great Promise ◽  
Functional Nanomaterials ◽  
Self Assembling ◽  
Low Toxicity ◽  
Bio Compatibility

Peptide drugs hold great promise for the treatment of infectious diseases thanks to their novel mechanisms of action, low toxicity, high specificity, and ease of synthesis and modification. Naturally developing self-assembly in nature has inspired remarkable interest in self-assembly of peptides to functional nanomaterials. As a matter of fact, their structural, mechanical, and functional advantages, plus their high bio-compatibility and bio-degradability make them excellent candidates for facilitating biomedical applications. This review focuses on the self-assembly of peptides for the fabrication of antibacterial nanomaterials holding great interest for substituting antibiotics, with emphasis on strategies to achieve nano-architectures of self-assembly. The antibacterial activities achieved by these nanomaterials are also described.

scholarly journals Stereocomplex Polylactide for Drug Delivery and Biomedical Applications: A Review

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2846
Author(s):  
Seung Hyuk Im ◽  
Dam Hyeok Im ◽  
Su Jeong Park ◽  
Justin Jihong Chung ◽  
Youngmee Jung ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Drug Carrier ◽  
Micelle Formation ◽  
Weak Stability ◽  
Critical Fields ◽  
Physical Strength ◽  
Anti Cancer

Polylactide (PLA) is among the most common biodegradable polymers, with applications in various fields, such as renewable and biomedical industries. PLA features poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) enantiomers, which form stereocomplex crystals through racemic blending. PLA emerged as a promising material owing to its sustainable, eco-friendly, and fully biodegradable properties. Nevertheless, PLA still has a low applicability for drug delivery as a carrier and scaffold. Stereocomplex PLA (sc-PLA) exhibits substantially improved mechanical and physical strength compared to the homopolymer, overcoming these limitations. Recently, numerous studies have reported the use of sc-PLA as a drug carrier through encapsulation of various drugs, proteins, and secondary molecules by various processes including micelle formation, self-assembly, emulsion, and inkjet printing. However, concerns such as low loading capacity, weak stability of hydrophilic contents, and non-sustainable release behavior remain. This review focuses on various strategies to overcome the current challenges of sc-PLA in drug delivery systems and biomedical applications in three critical fields, namely anti-cancer therapy, tissue engineering, and anti-microbial activity. Furthermore, the excellent potential of sc-PLA as a next-generation polymeric material is discussed.

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