In vitro electrochemical characterization of polydopamine melanin as a tissue stimulating electrode material

Bettinger

2018

J. Mater. Chem. B

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Section: Figmentioning

confidence: 99%

Polydopamine nanostructures as biomaterials for medical applications

Bettinger

2018

J. Mater. Chem. B

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“…Deposition procedures were repeated until the desired nominal film thickness was achieved. For example, a total of four cycles were used to achieve a PDM film thickness of 200 ± 20 nm …”

Section: Methodsmentioning

confidence: 99%

“…For example, a total of four cycles were used to achieve a PDM film thickness of 200 ± 20 nm. 31 Electrochemical characterization of PDM-coated stainless steel membranes PDM-coated stainless steel membranes were cut into square coupons with nominal surface areas of 3 cm × 3 cm, which accommodate a total of 150 microwires. PDM-coated stainless steel membranes were used as the working electrode with platinum foil as the counter electrode and MSE reference electrode.…”

Section: Synthesis Of Redox-active Polydopamine Melanin (Pdm) Membranesmentioning

confidence: 99%

Lithium purification from aqueous solutions using bioinspired redox‐active melanin membranes

Park

Kim

et al. 2016

Polymer International

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The separation of lithium from magnesium ions in salt brines is an important step in producing raw lithium for prospective use in electrochemical storage systems. Liquid–liquid extraction of Mg2+ ions from Li+ ions is challenging because of comparable thermodynamic behavior in aqueous solutions. Removing Mg2+ ions from brines using consumable ion‐exchange membranes is also a challenging prospect due to poor chemical selectivity and compromised sustainability. Here, we propose the use of redox‐active catechols in the form of melanin pigments for selective removal of Mg2+ ions from aqueous solutions. Synthetic melanin films are oxidatively polymerized on stainless steel meshes from aqueous solutions of dopamine precursors to create electrochemically functionalized polydopamine membranes. The binding selectivity of redox‐active catechol‐bearing polydopamine melanin for Mg2+ ions in aqueous solutions was measured as a function of electrochemical cycling. The binding kinetics of Mg2+ ions to polydopamine pigments was measured. Mg2+ ions binding selectivity to polydopamine in mixed aqueous solutions containing both Li+ and Mg2+ ions were also measured. Additionally, the equilibrium binding concentrations of Mg2+ ions to polydopamine were achieved very rapidly (<1 min). Redox‐active polydopamine membranes therefore show promise as functional materials for the separation of Mg2+ and Li+ ions in aqueous solutions. © 2016 Society of Chemical Industry

“…Charge transfer is therefore likely governed by non-Faradaic charging and discharging of double layers on the electrode surface. [101] Further, Pt electrodes transfer printed to adhesive hydrogel-based substrates exhibit lower impedance values for f < 100 Hz compared to Pt electrodes fabricated directly on rigid planar glass substrates.…”

Section: Mechanical and Electrical Properties Of Hydrogel-based Multielectrode Arraysmentioning

confidence: 99%

Ultracompliant Hydrogel‐Based Neural Interfaces Fabricated by Aqueous‐Phase Microtransfer Printing

Huang

Ong

et al. 2018

Adv Funct Materials

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Hydrogel-based electronics are ideally suited for neural interfaces because they exhibit ultracompliant mechanical properties that match that of excitable tissue in the brain and peripheral nerve. Hydrogel-based multielectrode arrays (MEA) can conformably interface with tissues to minimize inflammation and improve the reliability to enhance signal transduction.However, MEA substrates composed of swollen hydrogels exhibit low toughness and low adhesion stability when laminated on the tissue surface and also present technical challenges for processes commonly employed in MEA fabrication. Here, we describe a new strategy to fabricate ultracompliant MEA based on aqueous-phase transfer printing. This technique employs redox active adhesive motifs in hygroscopic polymer precursors that simultaneously form hydrogels through sol-gel phase transitions and bond to underlying microelectronic structures. Specifically, in situ gelation of 4-arm-polyethylene glycol-grafted catechol [PEG-Dopa]4 hydrogels induced by oxidation using Fe 3+ produces conformal adhesive contact with the underlying MEA, robust adhesion to electronic structures, and rapid dissolution of watersoluble sacrificial release layers. MEA are then integrated on hydrogel-based substrates to produce free standing ultracompliant neural probes, which are then laminated to the surface of the dorsal root ganglia in feline subjects to record single-unit neural activity.