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1.
Proc Natl Acad Sci U S A ; 116(43): 21427-21437, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31601737

RESUMO

Pharmacology and optogenetics are widely used in neuroscience research to study the central and peripheral nervous systems. While both approaches allow for sophisticated studies of neural circuitry, continued advances are, in part, hampered by technology limitations associated with requirements for physical tethers that connect external equipment to rigid probes inserted into delicate regions of the brain. The results can lead to tissue damage and alterations in behavioral tasks and natural movements, with additional difficulties in use for studies that involve social interactions and/or motions in complex 3-dimensional environments. These disadvantages are particularly pronounced in research that demands combined optogenetic and pharmacological functions in a single experiment. Here, we present a lightweight, wireless, battery-free injectable microsystem that combines soft microfluidic and microscale inorganic light-emitting diode probes for programmable pharmacology and optogenetics, designed to offer the features of drug refillability and adjustable flow rates, together with programmable control over the temporal profiles. The technology has potential for large-scale manufacturing and broad distribution to the neuroscience community, with capabilities in targeting specific neuronal populations in freely moving animals. In addition, the same platform can easily be adapted for a wide range of other types of passive or active electronic functions, including electrical stimulation.


Assuntos
Optogenética/métodos , Farmacologia/métodos , Animais , Encéfalo/metabolismo , Química Encefálica , Channelrhodopsins/metabolismo , Estimulação Elétrica , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Optogenética/instrumentação , Farmacologia/instrumentação , Próteses e Implantes , Tecnologia sem Fio/instrumentação
2.
Adv Mater ; 31(42): e1902739, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31489737

RESUMO

Transient forms of electronics, systems that disintegrate, dissolve, resorb, or sublime in a controlled manner after a well-defined operating lifetime, are of interest for applications in hardware secure technologies, temporary biomedical implants, "green" consumer devices and other areas that cannot be addressed with conventional approaches. Broad sets of materials now exist for a range of transient electronic components, including transistors, diodes, antennas, sensors, and even batteries. This work reports the first examples of transient light-emitting diodes (LEDs) that can completely dissolve in aqueous solutions to biologically and environmentally benign end products. Thin films of highly textured ZnO and polycrystalline Mo serve as semiconductors for light generation and conductors for transparent electrodes, respectively. The emitted light spans a range of visible wavelengths, where nanomembranes of monocrystalline silicon can serve as transient filters to yield red, green, and blue LEDs. Detailed characterization of the material chemistries and morphologies of the constituent layers, assessments of their performance properties, and studies of their dissolution processes define the underlying aspects. These results establish an electroluminescent light source technology for unique classes of optoelectronic systems that vanish into benign forms when exposed to aqueous conditions in the environment or in living organisms.


Assuntos
Semicondutores , Molibdênio/química , Fenômenos Ópticos , Solubilidade , Água/química , Óxido de Zinco/química
3.
Sci Adv ; 5(7): eaaw5296, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31281895

RESUMO

Studies of the peripheral nervous system rely on controlled manipulation of neuronal function with pharmacologic and/or optogenetic techniques. Traditional hardware for these purposes can cause notable damage to fragile nerve tissues, create irritation at the biotic/abiotic interface, and alter the natural behaviors of animals. Here, we present a wireless, battery-free device that integrates a microscale inorganic light-emitting diode and an ultralow-power microfluidic system with an electrochemical pumping mechanism in a soft platform that can be mounted onto target peripheral nerves for programmed delivery of light and/or pharmacological agents in freely moving animals. Biocompliant designs lead to minimal effects on overall nerve health and function, even with chronic use in vivo. The small size and light weight construction allow for deployment as fully implantable devices in mice. These features create opportunities for studies of the peripheral nervous system outside of the scope of those possible with existing technologies.


Assuntos
Encéfalo/fisiopatologia , Optogenética/métodos , Nervos Periféricos , Tecnologia sem Fio , Animais , Humanos , Camundongos , Neurotransmissores/farmacologia , Próteses e Implantes
4.
Sensors (Basel) ; 18(2)2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29389857

RESUMO

Postural control is a complex skill based on the interaction of dynamic sensorimotor processes, and can be challenging for people with deficits in sensory functions. The foot plantar center of pressure (COP) has often been used for quantitative assessment of postural control. Previously, the foot plantar COP was mainly measured by force plates or complicated and expensive insole-based measurement systems. Although some low-cost instrumented insoles have been developed, their ability to accurately estimate the foot plantar COP trajectory was not robust. In this study, a novel individual-specific nonlinear model was proposed to estimate the foot plantar COP trajectories with an instrumented insole based on low-cost force sensitive resistors (FSRs). The model coefficients were determined by a least square error approximation algorithm. Model validation was carried out by comparing the estimated COP data with the reference data in a variety of postural control assessment tasks. We also compared our data with the COP trajectories estimated by the previously well accepted weighted mean approach. Comparing with the reference measurements, the average root mean square errors of the COP trajectories of both feet were 2.23 mm (±0.64) (left foot) and 2.72 mm (±0.83) (right foot) along the medial-lateral direction, and 9.17 mm (±1.98) (left foot) and 11.19 mm (±2.98) (right foot) along the anterior-posterior direction. The results are superior to those reported in previous relevant studies, and demonstrate that our proposed approach can be used for accurate foot plantar COP trajectory estimation. This study could provide an inexpensive solution to fall risk assessment in home settings or community healthcare center for the elderly. It has the potential to help prevent future falls in the elderly.


Assuntos
Pé/fisiologia , Dispositivos Eletrônicos Vestíveis/economia , Dispositivos Eletrônicos Vestíveis/normas , Fenômenos Biomecânicos , Humanos , Dinâmica não Linear , Pressão , Sapatos
5.
J Nanosci Nanotechnol ; 15(6): 4604-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26369087

RESUMO

The optical and structural properties of InGaN/GaN multi-quantum wells (MQWs) grown on sapphire by metalorganic chemical vapor deposition (MOCVD) have been investigated by optical measure- ments of photoluminescence (PL), and structural analysis methods of high-resolution X-ray diffrac- tion (HRXRD) and high-resolution transmission electron microscopy (HRTEM). Two typical samples are studied, both consisting of five periods of GaN barrier width of 11.8 nm with different InGaN well width of 2.95 nm and 1.7 nm. These results indicate that the crystal and optical properties of InGaN/GaN MQWs are improved with the narrower of the InGaN well width. The indium compositions, GaN barrier width and InGaN well width can be achieved by HRXRD simulation software, and the result is consistent with actual growth conditions of InGaN/GaN MQWs.

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