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1.
Int J Nanomedicine ; 15: 8037-8043, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33116516

RESUMO

Background: Artificial synaptic behaviors are necessary to investigate and implement since they are considered to be a new computing mechanism for the analysis of complex brain information. However, flexible and transparent artificial synapse devices based on thin-film transistors (TFTs) still need further research. Purpose: To study the application of flexible and transparent thin-film transistors with nanometer thickness on artificial synapses. Materials and Methods: Here, we report the design and fabrication of flexible and transparent artificial synapse devices based on TFTs with polyethylene terephthalate (PET) as the flexible substrate, indium tin oxide (ITO) as the gate and a polyvinyl alcohol (PVA) grid insulating layer as the gate insulation layer at room temperature. Results: The charge and discharge of the carriers in the flexible and transparent thin-film transistors with nanometer thickness can be used for artificial synaptic behavior. Conclusion: In summary, flexible and transparent thin-film transistors with nanometer thickness can be used as pressure and temperature sensors. Besides, inherent charge transfer characteristics of indium gallium zinc oxide semiconductors have been employed to study the biological synapse-like behaviors, including synaptic plasticity, excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), and long-term memory (LTM). More precisely, the spike rate plasticity (SRDP), one representative synaptic plasticity, has been demonstrated. Such TFTs are interesting for building future neuromorphic systems and provide a possibility to act as fundamental blocks for neuromorphic system applications.


Assuntos
Nanopartículas/química , Nanotecnologia/instrumentação , Transistores Eletrônicos , Eletrodos , Gálio/química , Índio/química , Maleabilidade , Compostos de Estanho/química , Óxido de Zinco/química
2.
Nat Commun ; 11(1): 4234, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843643

RESUMO

Brain-machine interfaces are promising tools to restore lost motor functions and probe brain functional mechanisms. As the number of recording electrodes has been exponentially rising, the signal processing capability of brain-machine interfaces is falling behind. One of the key bottlenecks is that they adopt conventional von Neumann architecture with digital computation that is fundamentally different from the working principle of human brain. In this work, we present a memristor-based neural signal analysis system, where the bio-plausible characteristics of memristors are utilized to analyze signals in the analog domain with high efficiency. As a proof-of-concept demonstration, memristor arrays are used to implement the filtering and identification of epilepsy-related neural signals, achieving a high accuracy of 93.46%. Remarkably, our memristor-based system shows nearly 400× improvements in the power efficiency compared to state-of-the-art complementary metal-oxide-semiconductor systems. This work demonstrates the feasibility of using memristors for high-performance neural signal analysis in next-generation brain-machine interfaces.


Assuntos
Interfaces Cérebro-Computador , Redes Neurais de Computação , Processamento de Sinais Assistido por Computador/instrumentação , Encéfalo/fisiologia , Computadores Analógicos , Sinapses Elétricas/fisiologia , Epilepsia/fisiopatologia , Humanos , Modelos Neurológicos , Transistores Eletrônicos
3.
Nat Commun ; 11(1): 4030, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32788588

RESUMO

Sensory information processing in robot skins currently rely on a centralized approach where signal transduction (on the body) is separated from centralized computation and decision-making, requiring the transfer of large amounts of data from periphery to central processors, at the cost of wiring, latency, fault tolerance and robustness. We envision a decentralized approach where intelligence is embedded in the sensing nodes, using a unique neuromorphic methodology to extract relevant information in robotic skins. Here we specifically address pain perception and the association of nociception with tactile perception to trigger the escape reflex in a sensorized robotic arm. The proposed system comprises self-healable materials and memtransistors as enabling technologies for the implementation of neuromorphic nociceptors, spiking local associative learning and communication. Configuring memtransistors as gated-threshold and -memristive switches, the demonstrated system features in-memory edge computing with minimal hardware circuitry and wiring, and enhanced fault tolerance and robustness.


Assuntos
Robótica , Processamento de Sinais Assistido por Computador , Transistores Eletrônicos , Potenciais de Ação/fisiologia , Lógica , Plasticidade Neuronal/fisiologia , Nociceptividade , Terminações Pré-Sinápticas/fisiologia
4.
Nat Commun ; 11(1): 3743, 2020 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-32719350

RESUMO

Ions are ubiquitous biological regulators playing a key role for vital processes in animals and plants. The combined detection of ion concentration and real-time monitoring of small variations with respect to the resting conditions is a multiscale functionality providing important information on health states. This multiscale functionality is still an open challenge for current ion sensing approaches. Here we show multiscale real-time and high-sensitivity ion detection with complementary organic electrochemical transistors amplifiers. The ion-sensing amplifier integrates in the same device both selective ion-to-electron transduction and local signal amplification demonstrating a sensitivity larger than 2300 mV V-1 dec-1, which overcomes the fundamental limit. It provides both ion detection over a range of five orders of magnitude and real-time monitoring of variations two orders of magnitude lower than the detected concentration, viz. multiscale ion detection. The approach is generally applicable to several transistor technologies and opens opportunities for multifunctional enhanced bioelectronics.


Assuntos
Amplificadores Eletrônicos , Sistemas Computacionais , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Íons/análise , Compostos Orgânicos/química , Transistores Eletrônicos , Eletricidade , Humanos , Íons/sangue , Potássio/análise
5.
Nat Commun ; 11(1): 3362, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620794

RESUMO

Intrinsically and fully stretchable active-matrix-driven displays are an important element to skin electronics that can be applied to many emerging fields, such as wearable electronics, consumer electronics and biomedical devices. Here, we show for the first time a fully stretchable active-matrix-driven organic light-emitting electrochemical cell array. Briefly, it is comprised of a stretchable light-emitting electrochemical cell array driven by a solution-processed, vertically integrated stretchable organic thin-film transistor active-matrix, which is enabled by the development of chemically-orthogonal and intrinsically stretchable dielectric materials. Our resulting active-matrix-driven organic light-emitting electrochemical cell array can be readily bent, twisted and stretched without affecting its device performance. When mounted on skin, the array can tolerate to repeated cycles at 30% strain. This work demonstrates the feasibility of skin-applicable displays and lays the foundation for further materials development.


Assuntos
Materiais Biomiméticos/química , Elastômeros/química , Transistores Eletrônicos , Dispositivos Eletrônicos Vestíveis , Eletroquímica , Éteres/química , Estudos de Viabilidade , Fluorcarbonetos/química , Luminescência , Teste de Materiais , Ácidos Polimetacrílicos/química , Pele
6.
Int J Nanomedicine ; 15: 3597-3603, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32547016

RESUMO

Background: Transparent thin-film transistors (TFTs) have received a great deal of attention for medical sensors, OLED and medical display applications. Moreover, ultrathin nanomaterial layers are favored due to their more compact design architectures. Methods: Here, transparent TFTs are proposed and were investigated under different stress conditions such as temperature and biases. Results: Key electrical characteristics of the sensors, such as threshold voltage changes, illustrate their linear dependence on temperature with a suitable recovery, suggesting the potential of the devices to serve as medical temperature sensors. The temperature conditions changed in the range of 28°C to 40°C, which is within the standard human temperature testing range. The thickness of the indium-gallium-zinc oxide semiconductor layer was as thin as only 5-6 nm, deposited by mature radio-frequency sputtering which also showed good repeatability. Optimal bending durability caused by mechanical deformation was demonstrated via suitable electrical properties after up to 600 bending cycles, and by testing the flexible device at a different bending radii ranging from 48 mm to 18 mm. Conclusion: In summary, this study suggests that the present transparent nano TFTs are promising candidates for medical sensors, OLED and displays which require transparency and stability.


Assuntos
Nanoestruturas/química , Nanotecnologia/métodos , Fenômenos Ópticos , Transistores Eletrônicos , Reprodutibilidade dos Testes , Temperatura
7.
Nat Commun ; 11(1): 3226, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32591504

RESUMO

Real-time, high resolution, simultaneous measurement of multiple ionic species is challenging with existing chromatographic, spectrophotometric and potentiometric techniques. Potentiometric ion sensors exhibit limitations in both resolution and selectivity. Herein, we develop wafer scale graphene transistor technology for overcoming these limitations. Large area graphene is an ideal material for high resolution ion sensitive field effect transistors (ISFETs), while simultaneously enabling facile fabrication as compared to conventional semiconductors. We develop the ISFETs into an array and apply Nikolskii-Eisenman analysis to account for cross-sensitivity and thereby achieve high selectivity. We experimentally demonstrate real-time, simultaneous concentration measurement of K+, Na+, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and Cl- with a resolution of [Formula: see text] concentration units. The array achieves an accuracy of  ±0.05 log concentration. Finally, we demonstrate real-time ion concentration measurement in an aquarium with lemnoideae lemna over three weeks, where mineral uptake by aquatic organisms can be observed during their growth.


Assuntos
Grafite/química , Eletrodos Íon-Seletivos , Transistores Eletrônicos , Ânions , Cátions , Eletrólitos/química , Concentração de Íons de Hidrogênio , Imagem Óptica , Temperatura , Fatores de Tempo
8.
Nat Commun ; 11(1): 2753, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32488078

RESUMO

Imbuing bio-inspired sensory devices with intelligent functions of human sensory organs has been limited by challenges in emulating the preprocessing abilities of sensory organs such as reception, filtering, adaptation, and sensory memory at the device level itself. Merkel cells, which is a part of tactile sensory organs, form synapse-like connections with afferent neuron terminals referred to as Merkel cell-neurite complexes. Here, inspired by structure and intelligent functions of Merkel cell-neurite complexes, we report a flexible, artificial, intrinsic-synaptic tactile sensory organ that mimics synapse-like connections using an organic synaptic transistor with ferroelectric nanocomposite gate dielectric of barium titanate nanoparticles and poly(vinylidene fluoride-trifluoroethylene). Modulation of the post-synaptic current of the device induced by ferroelectric dipole switching due to triboelectric-capacitive coupling under finger touch allowed reception and slow adaptation. Modulation of synaptic weight by varying the nanocomposite composition of gate dielectric layer enabled tuning of filtering and sensory memory functions.


Assuntos
Órgãos Artificiais , Células Receptoras Sensoriais/fisiologia , Tato/fisiologia , Técnicas Biossensoriais/instrumentação , Humanos , Aprendizagem/fisiologia , Memória/fisiologia , Células de Merkel , Neuritos , Sinapses/fisiologia , Percepção do Tato , Transistores Eletrônicos
9.
J Vis Exp ; (159)2020 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-32510476

RESUMO

Aluminum-oxide (Al2O3) is a low cost, easily processable and high dielectric constant insulating material that is particularly appropriate for use as the dielectric layer of thin-film transistors (TFTs). Growth of aluminum-oxide layers from anodization of metallic aluminum films is greatly advantageous when compared to sophisticated processes such as atomic layer deposition (ALD) or deposition methods that demand relatively high temperatures (above 300 °C) such as aqueous combustion or spray-pyrolysis. However, the electrical properties of the transistors are highly dependent on the presence of defects and localized states at the semiconductor/dielectric interface, which are strongly affected by the manufacturing parameters of the anodized dielectric layer. To determine how several fabrication parameters influence the device performance without performing all possible combination of factors, we used a reduced factorial analysis based on a Plackett-Burman design of experiments (DOE). The choice of this DOE permits the use of only 12 experimental runs of combinations of factors (instead of all 256 possibilities) to obtain the optimized device performance. The ranking of the factors by the effect on device responses such as the TFT mobility is possible by applying analysis of variance (ANOVA) to the obtained results.


Assuntos
Óxido de Alumínio/química , Condutividade Elétrica , Eletrodos , Transistores Eletrônicos , Desenho de Equipamento
10.
ACS Nano ; 14(4): 5135-5142, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: covidwho-59591

RESUMO

Coronavirus disease 2019 (COVID-19) is a newly emerging human infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously called 2019-nCoV). Based on the rapid increase in the rate of human infection, the World Health Organization (WHO) has classified the COVID-19 outbreak as a pandemic. Because no specific drugs or vaccines for COVID-19 are yet available, early diagnosis and management are crucial for containing the outbreak. Here, we report a field-effect transistor (FET)-based biosensing device for detecting SARS-CoV-2 in clinical samples. The sensor was produced by coating graphene sheets of the FET with a specific antibody against SARS-CoV-2 spike protein. The performance of the sensor was determined using antigen protein, cultured virus, and nasopharyngeal swab specimens from COVID-19 patients. Our FET device could detect the SARS-CoV-2 spike protein at concentrations of 1 fg/mL in phosphate-buffered saline and 100 fg/mL clinical transport medium. In addition, the FET sensor successfully detected SARS-CoV-2 in culture medium (limit of detection [LOD]: 1.6 × 101 pfu/mL) and clinical samples (LOD: 2.42 × 102 copies/mL). Thus, we have successfully fabricated a promising FET biosensor for SARS-CoV-2; our device is a highly sensitive immunological diagnostic method for COVID-19 that requires no sample pretreatment or labeling.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Transistores Eletrônicos , Técnicas de Laboratório Clínico , Grafite , Humanos , Nanotecnologia/instrumentação , Cavidade Nasal , Pandemias , Manejo de Espécimes
11.
ACS Nano ; 14(4): 5135-5142, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32293168

RESUMO

Coronavirus disease 2019 (COVID-19) is a newly emerging human infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously called 2019-nCoV). Based on the rapid increase in the rate of human infection, the World Health Organization (WHO) has classified the COVID-19 outbreak as a pandemic. Because no specific drugs or vaccines for COVID-19 are yet available, early diagnosis and management are crucial for containing the outbreak. Here, we report a field-effect transistor (FET)-based biosensing device for detecting SARS-CoV-2 in clinical samples. The sensor was produced by coating graphene sheets of the FET with a specific antibody against SARS-CoV-2 spike protein. The performance of the sensor was determined using antigen protein, cultured virus, and nasopharyngeal swab specimens from COVID-19 patients. Our FET device could detect the SARS-CoV-2 spike protein at concentrations of 1 fg/mL in phosphate-buffered saline and 100 fg/mL clinical transport medium. In addition, the FET sensor successfully detected SARS-CoV-2 in culture medium (limit of detection [LOD]: 1.6 × 101 pfu/mL) and clinical samples (LOD: 2.42 × 102 copies/mL). Thus, we have successfully fabricated a promising FET biosensor for SARS-CoV-2; our device is a highly sensitive immunological diagnostic method for COVID-19 that requires no sample pretreatment or labeling.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Transistores Eletrônicos , Técnicas de Laboratório Clínico , Grafite , Humanos , Nanotecnologia/instrumentação , Cavidade Nasal , Pandemias , Manejo de Espécimes
12.
Nat Commun ; 11(1): 1543, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32210235

RESUMO

Field-effect transistor (FET)-based biosensors allow label-free detection of biomolecules by measuring their intrinsic charges. The detection limit of these sensors is determined by the Debye screening of the charges from counter ions in solutions. Here, we use FETs with a deformed monolayer graphene channel for the detection of nucleic acids. These devices with even millimeter scale channels show an ultra-high sensitivity detection in buffer and human serum sample down to 600 zM and 20 aM, respectively, which are ∼18 and ∼600 nucleic acid molecules. Computational simulations reveal that the nanoscale deformations can form 'electrical hot spots' in the sensing channel which reduce the charge screening at the concave regions. Moreover, the deformed graphene could exhibit a band-gap, allowing an exponential change in the source-drain current from small numbers of charges. Collectively, these phenomena allow for ultrasensitive electronic biomolecular detection in millimeter scale structures.


Assuntos
Técnicas Biossensoriais/instrumentação , Sondas de DNA/análise , DNA de Cadeia Simples/análise , Grafite/química , MicroRNAs/análise , Sondas de DNA/química , DNA de Cadeia Simples/química , Estudos de Viabilidade , Humanos , Íons , Limite de Detecção , MicroRNAs/química , Simulação de Dinâmica Molecular , Sensibilidade e Especificidade , Transistores Eletrônicos
13.
Biosensors (Basel) ; 10(3)2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32192133

RESUMO

The olfactory receptor neurons of insects and vertebrates are gated by odorant receptor (OR) proteins of which several members have been shown to exhibit remarkable sensitivity and selectivity towards volatile organic compounds of significant importance in the fields of medicine, agriculture and public health. Insect ORs offer intrinsic amplification where a single binding event is transduced into a measurable ionic current. Consequently, insect ORs have great potential as biorecognition elements in many sensor configurations. However, integrating these sensing components onto electronic transducers for the development of biosensors has been marginal due to several drawbacks, including their lipophilic nature, signal transduction mechanism and the limited number of known cognate receptor-ligand pairs. We review the current state of research in this emerging field and highlight the use of a group of indole-sensitive ORs (indolORs) from unexpected sources for the development of biosensors.


Assuntos
Insetos/metabolismo , Receptores Odorantes/análise , Compostos Orgânicos Voláteis/química , Animais , Técnicas Biossensoriais , Proteínas de Insetos/análise , Nanotubos de Carbono/química , Transdutores , Transistores Eletrônicos
14.
Sci Rep ; 10(1): 3772, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111933

RESUMO

In this study, ultrasensitive and precise detection of a representative brain hormone, dopamine (DA), was demonstrated using functional conducting polymer nanotubes modified with aptamers. A high-performance aptasensor was composed of interdigitated microelectrodes (IMEs), carboxylated polypyrrole nanotubes (CPNTs) and DA-specific aptamers. The biosensors were constructed by sequential conjugation of CPNTs and aptamer molecules on the IMEs, and the substrate was integrated into a liquid-ion gating system surrounded by pH 7.4 buffer as an electrolyte. To confirm DA exocytosis based on aptasensors, DA sensitivity and selectivity were monitored using liquid-ion gated field-effect transistors (FETs). The minimum detection level (MDL; 100 pM) of the aptasensors was determined, and their MDL was optimized by controlling the diameter of the CPNTs owing to their different capacities for aptamer introduction. The MDL of CPNT aptasensors is sufficient for discriminating between healthy and unhealthy individuals because the total DA concentration in the blood of normal person is generally determined to be ca. 0.5 to 6.2 ng/mL (3.9 to 40.5 nM) by high-performance liquid chromatography (HPLC) (this information was obtained from a guidebook "Evidence-Based Medicine 2018 SCL " which was published by Seoul Clinical Laboratory). The CPNTs with the smaller diameters (CPNT2: ca. 120 nm) showed 100 times higher sensitivity and selectivity than the wider CPNTs (CPNT1: ca. 200 nm). Moreover, the aptasensors based on CPNTs had excellent DA discrimination in the presence of various neurotransmitters. Based on the excellent sensing properties of these aptasensors, the DA levels of exogeneous DA samples that were prepared from PC12 cells by a DA release assay were successfully measured by DA kits, and the aptasensor sensing properties were compared to those of standard DA reagents. Finally, the real-time response values to the various exogeneous DA release levels were similar to those of a standard DA aptasensor. Therefore, CPNT-based aptasensors provide efficient and rapid DA screening for neuron-mediated genetic diseases such as Parkinson's disease.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , Dopamina , Exocitose , Nanotubos/química , Animais , Dopamina/análise , Dopamina/metabolismo , Células PC12 , Pirróis/química , Ratos , Transistores Eletrônicos
15.
PLoS One ; 15(2): e0225408, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32023244

RESUMO

A high-voltage generator (HVG) is an essential part of a radio frequency identification electrically erasable programmable read-only memory (RFID-EEPROM). An HVG circuit is used to generate a regulated output voltage that is higher than the power supply voltage. However, the performance of the HVG is affected owing to the high-power dissipation, high-ripple voltage and low-pumping efficiency. Therefore, a regulator circuit consists of a voltage divider, comparator and a voltage reference, which are respectively required to reduce the ripple voltage, increase pumping efficiency and decrease the power dissipation of the HVG. Conversely, a clock driving circuit consists of the current-starved ring oscillator (CSRO), and the non- overlapping clock generator is required to drive the clock signals of the HVG circuit. In this study, the Mentor Graphics EldoSpice software package is used to design and simulate the HVG circuitry. The results showed that the designed CSRO dissipated only 4.9 µW at 10.2 MHz and that the phase noise was only -119.38 dBc/Hz at 1 MHz. Moreover, the proposed charge pump circuit was able to generate a maximum VPP of 13.53 V and it dissipated a power of only 31.01 µW for an input voltage VDD of 1.8 V. After integrating all the HVG modules, the results showed that the regulated HVG circuit was also able to generate a higher VPP of 14.59 V, while the total power dissipated was only 0.12 mW with a chip area of 0.044 mm2. Moreover, the HVG circuit produced a pumping efficiency of 90% and reduced the ripple voltage to <4 mV. Therefore, the integration of all the proposed modules in HVG ensured low-ripple programming voltages, higher pumping efficiency, and EEPROMs with lower power dissipation, and can be extensively used in low-power applications, such as in non-volatile memory, radiofrequency identification transponders, on-chip direct current DC-DC converters.


Assuntos
Fontes de Energia Elétrica , Desenho de Equipamento/métodos , Dispositivo de Identificação por Radiofrequência , Software , Eletricidade , Ondas de Rádio , Transistores Eletrônicos
16.
Nat Commun ; 11(1): 1103, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-32107376

RESUMO

Lipid-protein complexes are the basis of pulmonary surfactants covering the respiratory surface and mediating gas exchange in lungs. Cardiolipin is a mitochondrial lipid overexpressed in mammalian lungs infected by bacterial pneumonia. In addition, increased oxygen supply (hyperoxia) is a pathological factor also critical in bacterial pneumonia. In this paper we fabricate a micrometer-size graphene-based sensor to measure oxygen permeation through pulmonary membranes. Combining oxygen sensing, X-ray scattering, and Atomic Force Microscopy, we show that mammalian pulmonary membranes suffer a structural transformation induced by cardiolipin. We observe that cardiolipin promotes the formation of periodic protein-free inter-membrane contacts with rhombohedral symmetry. Membrane contacts, or stalks, promote a significant increase in oxygen gas permeation which may bear significance for alveoli gas exchange imbalance in pneumonia.


Assuntos
Cardiolipinas/metabolismo , Grafite/química , Bicamadas Lipídicas/metabolismo , Oxigênio/metabolismo , Alvéolos Pulmonares/metabolismo , Animais , Permeabilidade da Membrana Celular/fisiologia , Humanos , Microscopia de Força Atômica/instrumentação , Microscopia Confocal/instrumentação , Microtecnologia/instrumentação , Pneumonia Bacteriana/fisiopatologia , Alvéolos Pulmonares/citologia , Alvéolos Pulmonares/ultraestrutura , Troca Gasosa Pulmonar/fisiologia , Espalhamento a Baixo Ângulo , Transistores Eletrônicos , Difração de Raios X/instrumentação
17.
Nat Commun ; 11(1): 326, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31949147

RESUMO

Bioinspired electronics are rapidly promoting advances in artificial intelligence. Emerging AI applications, e.g., autopilot and robotics, increasingly spur the development of power devices with new forms. Here, we present a strain-controlled power device that can directly modulate the output power responses to external strain at a rapid speed, as inspired by human reflex. By using the cantilever-structured AlGaN/AlN/GaN-based high electron mobility transistor, the device can control significant output power modulation (2.30-2.72 × 103 W cm-2) with weak mechanical stimuli (0-16 mN) at a gate bias of 1 V. We further demonstrate the acceleration-feedback-controlled power application, and prove that the output power can be effectively adjusted at real-time in response to acceleration changes, i.e., ▵P of 72.78-132.89 W cm-2 at an acceleration of 1-5 G at a supply voltage of 15 V. Looking forward, the device will have great significance in a wide range of AI applications, including autopilot, robotics, and human-machine interfaces.


Assuntos
Inteligência Artificial , Reflexo/fisiologia , Robótica/instrumentação , Robótica/métodos , Transistores Eletrônicos , Compostos de Alumínio/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Elétrons , Gálio/química , Humanos
18.
Sci China Life Sci ; 63(8): 1159-1167, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31974862

RESUMO

Various nanobiosensors composed of biomaterials and nanomaterials have been developed, due to their demonstrated advantage of showing high performance. Among various biomaterials for biological recognition elements of the nanobiosensor, sensory receptors, such as olfactory and taste receptors, are promising biomaterials for developing nanobiosensors, because of their high selectivity to target molecules. Field-effect transistors (FET) with nanomaterials such as carbon nanotube (CNT), graphene, and conducting polymer nanotube (CPNT), can be combined with the biomaterials to enhance the sensitivity of nanobiosensors. Recently, many efforts have been made to develop nanobiosensors using biomaterials, such as olfactory receptors and taste receptors for detecting various smells and tastes. This review focuses on the biomaterials and nanomaterials used in nanobiosensor systems and studies of various types of nanobiosensor platforms that utilize olfactory receptors and taste receptors which could be applied to a wide range of industrial fields, including the food and beverage industry, environmental monitoring, the biomedical field, and anti-terrorism.


Assuntos
Materiais Biocompatíveis/química , Técnicas Biossensoriais/instrumentação , Nanoestruturas/química , Nanotecnologia/instrumentação , Transistores Eletrônicos , Condutividade Elétrica , Desenho de Equipamento , Humanos , Proteínas Imobilizadas/metabolismo , Polímeros/química , Receptores Acoplados a Proteínas-G/metabolismo , Receptores Odorantes/metabolismo , Olfato , Propriedades de Superfície , Paladar
19.
Sci Rep ; 10(1): 388, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31942024

RESUMO

Hormones within very low levels regulate and control the activity of specific cells and organs of the human body. Hormone imbalance can cause many diseases. Therefore, hormone detection tools have been developed, particularly over the last decade. Peptide hormones have a short half-life, so it is important to detect them within a short time. In this study, we report two types of peptide hormone sensors using human hormone receptor-carrying nanovesicles and graphene field-effect transistors (FETs). Parathyroid hormone (PTH) and glucagon (GCG) are peptide hormones present in human blood that act as ligands to G protein-coupled receptors (GPCRs). In this paper, the parathyroid hormone receptor (PTHR) and the glucagon receptor (GCGR) were expressed in human embryonic kidney-293 (HEK-293) cells, and were constructed as nanovesicles carrying the respective receptors. They were then immobilized onto graphene-based FETs. The two hormone sensors developed were able to detect each target hormone with high sensitivity (ca. 100 fM of PTH and 1 pM of GCG). Also, the sensors accurately recognized target hormones among different types of peptide hormones. In the development of hormone detection tools, this approach, using human hormone receptor-carrying nanovesicles and graphene FETs, offers the possibility of detecting very low concentrations of hormones in real-time.


Assuntos
Técnicas Biossensoriais/métodos , Grafite/química , Nanopartículas/química , Hormônios Peptídicos/análise , Receptores de Peptídeos/metabolismo , Transistores Eletrônicos , Células HEK293 , Humanos , Hormônios Peptídicos/metabolismo , Receptores de Peptídeos/química
20.
Biosens Bioelectron ; 148: 111796, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31665672

RESUMO

We present a new strategy of Acetylcholinesterease (AchE) immobilization on graphene field-effect transistors (gFETs) for building up Acetylcholine sensors. This method is based on the electrosynthesis of an amino moiety-bearing polymer layer on the graphene channel. The film of the copolymer poly(3-amino-benzylamine-co-aniline) (PABA) does not only provide the suitable electrostatic charge and non-denaturing environment for enzyme immobilization, but it also improves the pH sensitivity of the gFETs (from 40.8 to 56.3 µA/pH unit), probably due to its wider effective pKa distribution. The local pH changes caused by the enzyme-catalyzed hydrolysis produce a shift in the Dirac point of the gFETs to more negative values, which are evidenced as differences in the gFET conductivity and thereby constituted the signal transduction mechanism of the modified transistors. In this way, the constructed biosensors showed a LOD of 2.3 µM and were able to monitor Ach in the range from 5 to 1000 µM in a flow configuration. Moreover, they showed a sensitivity of -26.6 ±â€¯0.7 µA/Ach decade and also exhibited a very low RSD of 2.6%, revealing good device-to-device reproducibility. The biosensors revealed an excellent selectivity to interferences known to be present in the extracellular milieu, and the response to Ach was recovered by 97.5% after the whole set of interferences injected. Finally, the biosensors showed a fast response time, with an average value of 130 s and a good long-term response.


Assuntos
Acetilcolina/análise , Técnicas Biossensoriais/instrumentação , Grafite/química , Polímeros/química , Transistores Eletrônicos , Acetilcolinesterase/química , Compostos de Anilina/química , Benzilaminas/química , Enzimas Imobilizadas/química , Desenho de Equipamento , Oxirredução , Polimerização , Água/análise
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