HectoSTAR μLED Optoelectrodes for Large-Scale, High-Precision In Vivo Opto-Electrophysiology.

Dynamic interactions within and across brain areas underlie behavioral and cognitive functions. To understand the basis of these processes, the activities of distributed local circuits inside the brain of a behaving animal must be synchronously recorded while the inputs to these circuits are precisely manipulated. Even though recent technological advances have enabled such large-scale recording capabilities, the development of the high-spatiotemporal-resolution and large-scale modulation techniques to accompany those recordings has lagged.

Novel diamond shuttle to deliver flexible neural probe with reduced tissue compression.

The ability to deliver flexible biosensors through the toughest membranes of the central and peripheral nervous system is an important challenge in neuroscience and neural engineering. Bioelectronic devices implanted through dura mater and thick epineurium would ideally create minimal compression and acute damage as they reach the neurons of interest. We demonstrate that a three-dimensional diamond shuttle can be easily made with a vertical support to deliver ultra-compliant polymer microelectrodes (4.

Flexible microelectrode array for interfacing with the surface of neural ganglia.

Objective: The dorsal root ganglia (DRG) are promising nerve structures for sensory neural interfaces because they provide centralized access to primary afferent cell bodies and spinal reflex circuitry. In order to harness this potential, new electrode technologies are needed which take advantage of the unique properties of DRG, specifically the high density of neural cell bodies at the dorsal surface. Here we report initial in vivo results from the development of a flexible non-penetrating polyimide electrode array interfacing with the surface of ganglia.

Solvothermal synthesis and controlled self-assembly of monodisperse titanium-based perovskite colloidal nanocrystals.

The rational design of monodisperse ferroelectric nanocrystals with controlled size and shape and their organization into hierarchical structures has been a critical step for understanding the polar ordering in nanoscale ferroelectrics, as well as the design of nanocrystal-based functional materials which harness the properties of individual nanoparticles and the collective interactions between them. We report here on the synthesis and self-assembly of aggregate-free, single-crystalline titanium-based perovskite nanoparticles with controlled morphology and surface composition by using a simple, easily scalable and highly versatile colloidal route. Single-crystalline, non-aggregated BaTiO3 colloidal nanocrystals, used as a model system, have been prepared under solvothermal conditions at temperatures as low as 180 °C.

Ferroelectric barium titanate nanocubes as capacitive building blocks for energy storage applications.

Highly uniform polymer-ceramic nanocomposite films with high energy density values were fabricated by exploiting the unique ability of monodomain, nonaggregated BaTiO3 colloidal nanocrystals to function as capacitive building blocks when dispersed into a weakly interacting dielectric matrix. Monodisperse, surface-functionalized ferroelectric 15 nm BaTiO3 nanoparticles have been selectively incorporated with a high packing density into poly(vinylidene fluoride-co-hexafluoropropene) (P(VDF-HFP)) leading to the formation of biphasic BaTiO3-P(VDF-HFP) nanocomposite films. A systematic investigation of the electrical properties of the nanocomposites by electrostatic force microscopy and conventional dielectric measurements reveals that polymer-ceramic film capacitor structures exhibit a ferroelectric relaxor-type behavior with an increased intrinsic energy density.

Dielectric properties of barium titanate supramolecular nanocomposites.

Nanostructured dielectric composites can be obtained by dispersing high permittivity fillers, barium titanate (BTO) nanocubes, within a supramolecular framework. Thin films of BTO supramolecular nanocomposites exhibit a dielectric permittivity (εr) as high as 15 and a relatively low dielectric loss of ∼0.1 at 1 kHz.