scholarly journals Quantifying neurotransmitter secretion at single-vesicle resolution using high-density complementary metal–oxide–semiconductor electrode array

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kevin A. White ◽  
Brian N. Kim

AbstractNeuronal exocytosis facilitates the propagation of information through the nervous system pertaining to bodily function, memory, and emotions. Using amperometry, the sub-millisecond dynamics of exocytosis can be monitored and the modulation of exocytosis due to drug treatment or neurodegenerative diseases can be studied. Traditional single-cell amperometry is a powerful technique for studying the molecular mechanisms of exocytosis, but it is both costly and labor-intensive to accumulate statistically significant data. To surmount these limitations, we have developed a silicon-based electrode array with 1024 on-chip electrodes that measures oxidative signal in 0.1 millisecond intervals. Using the developed device, we are able to capture the modulation of exocytosis due to Parkinson’s disease treatment (L-Dopa), with statistical significance, within 30 total minutes of recording. The validation study proves our device’s capability to accelerate the study of many pharmaceutical treatments for various neurodegenerative disorders that affect neurotransmitter secretion to a matter of minutes.

Nanophotonics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 467-474 ◽  
Author(s):  
Wenhao Wu ◽  
Yu Yu ◽  
Wei Liu ◽  
Xinliang Zhang

AbstractPolarization measurement has been widely used in material characterization, medical diagnosis and remote sensing. However, existing commercial polarization analyzers are either bulky schemes or operate in non-real time. Recently, various polarization analyzers have been reported using metal metasurface structures, which require elaborate fabrication and additional detection devices. In this paper, a compact and fully integrated silicon polarization analyzer with a photonic crystal-like metastructure for polarization manipulation and four subsequent on-chip photodetectors for light-current conversion is proposed and demonstrated. The input polarization state can be retrieved instantly by calculating four output photocurrents. The proposed polarization analyzer is complementary metal oxide semiconductor-compatible, making it possible for mass production and easy integration with other silicon-based devices monolithically. Experimental verification is also performed for comparison with a commercial polarization analyzer, and deviations of the measured polarization angle are <±1.2%.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Popa ◽  
Richard Hopper ◽  
Syed Zeeshan Ali ◽  
Matthew Thomas Cole ◽  
Ye Fan ◽  
...  

AbstractThe gas sensor market is growing fast, driven by many socioeconomic and industrial factors. Mid-infrared (MIR) gas sensors offer excellent performance for an increasing number of sensing applications in healthcare, smart homes, and the automotive sector. Having access to low-cost, miniaturized, energy efficient light sources is of critical importance for the monolithic integration of MIR sensors. Here, we present an on-chip broadband thermal MIR source fabricated by combining a complementary metal oxide semiconductor (CMOS) micro-hotplate with a dielectric-encapsulated carbon nanotube (CNT) blackbody layer. The micro-hotplate was used during fabrication as a micro-reactor to facilitate high temperature (>700 $$^{\circ }$$ ∘ C) growth of the CNT layer and also for post-growth thermal annealing. We demonstrate, for the first time, stable extended operation in air of devices with a dielectric-encapsulated CNT layer at heater temperatures above 600 $$^{\circ }$$ ∘ C. The demonstrated devices exhibit almost unitary emissivity across the entire MIR spectrum, offering an ideal solution for low-cost, highly-integrated MIR spectroscopy for the Internet of Things.


2021 ◽  
Author(s):  
Daniel Popa ◽  
Richard Hopper ◽  
Syed Zeeshan Ali ◽  
Matthew Cole ◽  
Ye Fan ◽  
...  

Abstract The gas sensor market is growing fast, driven by many socioeconomic and industrial factors. Mid-infrared (MIR) gas sensors offer excellent performance for an increasing number of sensing applications in healthcare, smart homes, and the automotive sector. Having access to low-cost, miniaturized, energy efficient light sources is of critical importance for the monolithic integration of MIR sensors. Here, we present an on-chip broadband thermal MIR source fabricated by combining a complementary metal oxide semiconductor (CMOS) micro-hotplate with a dielectric-encapsulated carbon nanotube (CNT) blackbody layer. The micro-hotplate was used during fabrication as a micro-reactor to facilitate high temperature (>700 • C) growth of the CNT layer and also for post-growth thermal annealing. We demonstrate, for the first time, stable extended operation in air of devices with a dielectric-encapsulated CNT layer at heater temperatures above 600 • C. The demonstrated devices exhibit almost unitary emissivity across the entire MIR spectrum, offering an ideal solution for low-cost, highly-integrated MIR spectroscopy for the Internet of Sensors.


2021 ◽  
Author(s):  
Yun-Da Hsieh ◽  
Jun-Han Lin ◽  
Richard Soref ◽  
Greg Sun ◽  
Hung-Hsiang Cheng ◽  
...  

Abstract Si-based electronic-photonic integrated circuits (EPICs), which are compatible with state-of-the-art complementary metal-oxide-semiconductor (CMOS) processes, offer promising opportunities for on-chip mid-infrared (MIR) photonic systems. However, the lack of efficient MIR optical modulators on Si hinders the utilization of MIR EPICs. Here, we clearly demonstrate the Franz-Keldysh (FK) effect in GeSn alloys and achieve on-Si MIR electro-absorption optical modulation using GeSn heterostructures. Our experimental and theoretical results verify that the direct bandgap energy of GeSn can be widely tuned by varying the Sn content, thereby realizing wavelength-tunable optical modulation in the MIR range with a figure-of-merit of Δα /α0 (FOM) greater than 1.5 and a broadband operating range greater than 140 nm. In contrast to conventional silicon-photonic modulators based on the plasma dispersion effect, our GeSn heterostructure demonstrates practical and effective FK MIR optical modulation on Si and helps unlock the potential of MIR EPICs for a wide range of applications.


Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 870 ◽  
Author(s):  
Shuang Xie ◽  
Albert Theuwissen

This paper analyzes and compensates for process and temperature dependency among a (Complementary Metal Oxide Semiconductor) CMOS image sensor (CIS) array. Both the analysis and compensation are supported with experimental results on the CIS’s dark current, dark signal non-uniformity (DSNU), and conversion gain (CG). To model and to compensate for process variations, process sensors based on pixel source follower (SF)’s transconductance gm,SF have been proposed to model and to be compared against the measurement results of SF gain ASF. In addition, ASF’s thermal dependency has been analyzed in detail. To provide thermal information required for temperature compensation, six scattered bipolar junction transistor (BJT)-based temperature sensors replace six image pixels inside the array. They are measured to have an untrimmed inaccuracy within ±0.5 ⁰C. Dark signal and CG’s thermal dependencies are compensated using the on-chip temperature sensors by at least 79% and 87%, respectively.


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