GaN-based micro-LED arrays on flexible substrates for optical cochlear implants

Goßler, Christian; Bierbrauer, Colin; Moser, Rüdiger; Kunzer, M.; Holc, Katarzyna; Pletschen, W.; Köhler, K.; Wagner, J.; Schwaerzle, Michael; Ruther, Patrick; Oliver, Paul; Neef, Jakob; Keppeler, Daniel; Hoch, Gerhard; Moser, Tobias; Schwarz, Ulrich

doi:10.1088/0022-3727/47/20/205401

Cited by 152 publications

(148 citation statements)

References 15 publications

Supporting

Mentioning

144

Contrasting

Unclassified

Order By: Relevance

“…This approach shows two major limitations: (i) the size of the implanted waveguide significantly damages the brain tissue, and (ii) it is not possible to redirect light in a different zone of the brain. Several alternative technological solutions have been developed recently to dynamically redirect light towards different locations of the brain tissue [8][9][10][11], including µ-Light Emitting Diodes [6,12,13], array of waveguides [14][15][16][17], bundle of optical fibers [18,19] or patterned illumination techniques [4,20,21].…”

Section: Introductionmentioning

confidence: 99%

Modal demultiplexing properties of tapered and nanostructured optical fibers for in vivo optogenetic control of neural activity

Patria

Sileo

Sabatini

et al. 2015

Biomed. Opt. Express

View full text Add to dashboard Cite

Optogenetic approaches to manipulate neural activity have revolutionized the ability of neuroscientists to uncover the functional connectivity underlying brain function. At the same time, the increasing complexity of in vivo optogenetic experiments has increased the demand for new techniques to precisely deliver light into the brain, in particular to illuminate selected portions of the neural tissue. Tapered and nanopatterned gold-coated optical fibers were recently proposed as minimally invasive multipoint light delivery devices, allowing for site-selective optogenetic stimulation in the mammalian brain [Pisanello et al., Neuron 82, 1245]. Here we demonstrate that the working principle behind these devices is based on the mode-selective photonic properties of the fiber taper. Using analytical and ray tracing models we model the finite conductance of the metal coating, and show that single or multiple optical windows located at specific taper sections can outcouple only specific subsets of guided modes injected into the fiber.

show abstract

Section: Introductionmentioning

confidence: 99%

Modal demultiplexing properties of tapered and nanostructured optical fibers for in vivo optogenetic control of neural activity

Patria

Sileo

Sabatini

et al. 2015

Biomed. Opt. Express

View full text Add to dashboard Cite

show abstract

“…This is expected to minimize tissue response in comparison with devices with more rugged topography (Cao et al 2013). The implementation of commercial bare LEDs rather than custommade devices leads to a pronounced decrease in development time and fabrication cost compared to more advanced approaches using thin-film LED technologies (Ayub et al 2016;Goßler et al 2014;Scharf et al 2016;Wu et al 2015). Despite the larger surface area of these probes with a cross-sectional area of 250×65 µm 2 , in comparison to probes implementing thin-film LEDs, with cross-sections down to 70×30 µm 2 (Wu et al 2015), an electrical to optical conversion efficiency of a better 17 % is achievable for optical stimulation.…”

Section: Resultsmentioning

confidence: 99%

“…These approaches enable the all-electrical control of the optical probes. Alternative probe concepts have been based on thin-film LEDs integrated on flexible substrates using transfer printing (Kim et al 2013) and wafer-level bonding (Goßler et al 2014) technologies, respectively. The latter approach was adapted by us to integrate the miniaturized micro-LEDs (µLEDs) on penetrating Si-based probe shanks (Ayub et al 2016).…”

Section: Introductionmentioning

confidence: 99%

“…This work proposes a modular approach to realizing penetrating neural probes with integrated LEDs. Instead of processing LED epilayers (Goßler et al 2014) (Scharf et al 2016;Wu et al 2015), commercially available LED chips (TR2227 CREE Durham, NC) were chosen for this probe design. The bare LED chips are based on highly efficient indium gallium nitride (InGaN) junction on silicon carbide substrates.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hybrid intracerebral probe with integrated bare LED chips for optogenetic studies

Ayub

Gentet

Fiáth

et al. 2017

Biomed Microdevices

Self Cite

View full text Add to dashboard Cite

This article reports on the development, i.e., the design, fabrication, and validation of an implantable optical neural probes designed for in vivo experiments relying on optogenetics. The probes comprise an array of ten bare light-emitting diode (LED) chips emitting at a wavelength of 460 nm and integrated along a flexible polyimidebased substrate stiffened using a micromachined ladder-like silicon structure. The resulting mechanical stiffness of the slender, 250-μm-wide, 65-μm-thick, and 5-and 8-mm-long probe shank facilitates its implantation into neural tissue.

show abstract

“…[1][2][3][4] The high efficiency, brightness, reliability, and stability, 5,6 even under harsh temperature conditions, make III-Nitride semiconductor LEDs ideal candidates for many applications in the consumer and automotive area. In combination with a converter and a pixel control unit, these lLED arrays can be used for adaptive front lighting systems (AFS).…”

mentioning

confidence: 99%

Micro-pixel light emitting diodes: Impact of the chip process on microscopic electro- and photoluminescence

Otto

Mounir

Nirschl

et al. 2015

Applied Physics Letters

View full text Add to dashboard Cite

We investigated the influence of a μ-pixelated chip process on the photoluminescence (PL) and electroluminescence (EL) of a monolithic InGaN/GaN based blue light emitting diode with a continuous n-GaN layer. Particularly, we observed the impact of the metallic p-contact on the PL emission wavelength. A PL wavelength shift in the order of 10 nm between contacted and isolated areas was assigned to screening of internal piezoelectric fields due to charge carrier accumulation. μPL and μEL mappings revealed correlated emission wavelength and intensity inhomogeneities, caused by the epitaxial growth process. The edges of single pixels were investigated in detail via resonant confocal bias-dependent μPL. No influence on the intensity was observed beyond 300 nm away from the edge, which indicated a good working edge passivation. Due to the low lateral p-GaN conductivity, the μPL intensity was enhanced at isolated areas.

show abstract

GaN-based micro-LED arrays on flexible substrates for optical cochlear implants

Cited by 152 publications

References 15 publications

Modal demultiplexing properties of tapered and nanostructured optical fibers for in vivo optogenetic control of neural activity

Modal demultiplexing properties of tapered and nanostructured optical fibers for in vivo optogenetic control of neural activity

Hybrid intracerebral probe with integrated bare LED chips for optogenetic studies

Micro-pixel light emitting diodes: Impact of the chip process on microscopic electro- and photoluminescence

Contact Info

Product

Resources

About