scholarly journals Novel Heat-Mitigating Chip-on-Probe for Brain Stimulation Behavior Experiments

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7334
Author(s):  
Seongwoog Oh ◽  
Jungsuek Oh

This paper proposes a novel design for a chip-on-probe with the aim of overcoming the heat dissipation effect during brain stimulations using modulated microwave signals. The temperature of the stimulus chip during normal operation is generally 40 °C–60 °C, which is sufficient to cause unintended temperature effects during stimulation. This effect is particularly fatal in brain stimulation applications that require repeated stimulation. This paper proposes, for the first time, a topology that vertically separates the stimulus chip generating the stimulus signal and the probe delivering the signal into the brain to suppress the heat transfer while simultaneously minimizing the radio frequency (RF) transmission loss. As the proposed chip-on-probe should be attached to the head of a small animal, an auxiliary board with a heat sink was carefully designed considering the weight that does not affect the behavior experiment. When the transition structures are properly designed, a heat sink can be mounted to maximize the cooling effect, reducing the temperature by more than 13 °C in a simulation when the heat generated by the chip is transferred to the brain, while the transition from the chip to the probe experiences a loss of 1.2 dB. Finally, the effectiveness of the proposed design is demonstrated by fabricating a chip with the 0.28 μm silicon-on-insulator (SOI) complementary metal–oxide–semiconductor (CMOS) process and a probe with a RT6010 printed-circuit board (PCB), showing a temperature reduction of 49.8 °C with a maximum output power of 11 dBm. In the proposed chip-on-probe device, the temperature formed in the area in contact with the brain is measured at 31.1 °C.

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4571 ◽  
Author(s):  
Jelena Loncarski ◽  
Vito Giuseppe Monopoli ◽  
Riccardo Leuzzi ◽  
Leposava Ristic ◽  
Francesco Cupertino

Wide bandgap (WBG) power devices such as silicon carbide (SiC) can viably supply high speed electrical drives, due to their capability to increase efficiency and reduce the size of the power converters. On the other hand, high frequency operation of the SiC devices emphasizes the effect of parasitics, which generates reflected wave transient overvoltage on motor terminals, reducing the life time and the reliability of electric drives. In this paper, a SiC metal-oxide-semiconductor field-effect transistor (MOSFET) based two level (2L) inverter is systematically studied and compared to the performance of Si insulated-gate bipolar transistor (IGBT) based three level (3L) neutral point clamped (NPC) inverter topologies, for high speed AC motor loads, in terms of efficiency, overvoltages, heat sink design, and cost. A fair comparison was introduced for the first time, having the same output voltage capabilities, output current total harmonic distortion (THD), and overvoltages for the three systems. The analysis indicated the convenience of using the SiC MOSFET based 2L inverter for lower output power. In the case of the maximum output power, the heat sink volume was found to be 20% higher for the 2L SiC based inverter when compared to 3L NPC topologies. Simulations were carried out by realistic dynamic models of power switch modules obtained from the manufacturer’s experimental tests and verified both in the LTspice and PLECS simulation packages.


Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1181 ◽  
Author(s):  
Simone Becchetti ◽  
Anna Richelli ◽  
Luigi Colalongo ◽  
Zsolt Kovacs-Vajna

This paper provides the results of a comprehensive comparison between complementary metal oxide semiconductor (CMOS) amplifiers with low susceptibility to electromagnetic interference (EMI). They represent the state-of-the-art in low EMI susceptibility design. An exhaustive scenario for EMI pollution has been considered: the injected interference can indeed directly reach the amplifier pins or can be coupled from the printed circuit board (PCB) ground. This is also a key point for evaluating the susceptibility from EMI coupled to the output pin. All of the amplifiers are re-designed in a United Microelectronics Corporation (UMC) 180 nm CMOS process in order to have a fair comparison. The topologies investigated and compared are basically derived from the Miller and the folded cascode ones, which are well-known and widely used by CMOS analog designers.


2014 ◽  
Vol 618 ◽  
pp. 543-547
Author(s):  
Zhou Yu ◽  
Xiang Ning Fan ◽  
Zai Jun Hua ◽  
Chen Xu

A power amplifier (PA) for multi-mode multi-standard transceiver which is implemented in a TSMC 0.18μm process is presented. The proposed PA uses matching compensation, lossy matching network and negative feedback technique to improve bandwidth. To achieve the linearity performance, the two-stage PA operates in Class-A regime. Simulation results show that the power amplifier achieves maximum output power of more than 24dBm in 0.7~2.6GHz. The output P1dBof the PA is larger than 22dBm. The simulated power gain is more than 27dB. The S11 is less than-10dB and the S22 is under-5dB.


2013 ◽  
Vol 562-565 ◽  
pp. 1052-1057 ◽  
Author(s):  
Xing Qiang Zhao ◽  
Zhi Yu Wen ◽  
Li Cheng Deng ◽  
Guo Xi Luo ◽  
Zheng Guo Shang ◽  
...  

A micro piezoelectric cantilever beam array is designed for vibration energy harvesting. A single degree of freedom analytical model is developed to predict the properties of the device and is verified by finite element method. The piezoelectric material Aluminum Nitride was chosen for the compatibility with the CMOS process. The devices consisting of 5 piezoelectric cantilever beams and one proof mass were fabricated using micromachining technology. The resonance frequency, voltage and power were tested at excitation acceleration of 5.0 g. The maximum output power of the device is 9.13 μW at the resonance frequency of 1315 Hz when piezoelectric beams are connected in parallel.


2017 ◽  
Vol 9 (8) ◽  
pp. 1667-1677 ◽  
Author(s):  
László Szilágyi ◽  
Guido Belfiore ◽  
Ronny Henker ◽  
Frank Ellinger

The design of an analog frontend including a receiver amplifier (RX) and laser diode driver (LDD) for optical communication system is described. The RX consists of a transimpedance amplifier, a limiting amplifier, and an output buffer (BUF). An offset compensation and common-mode control circuit is designed using switched-capacitor technique to save chip area, provides continuous reduction of the offset in the RX. Active-peaking methods are used to enhance the bandwidth and gain. The very low gate-oxide breakdown voltage of transistors in deep sub-micron technologies is overcome in the LDD by implementing a topology which has the amplifier placed in a floating well. It comprises a level shifter, a pre-amplifier, and the driver stage. The single-chip frontend, fabricated in a 28 nm bulk-digital complementary metal–oxide–semiconductor (CMOS) process has a total active area of 0.003 mm2, is among the smallest optical frontends. Without the BUF, which consumes 8 mW from a separate supply, the RX power consumption is 21 mW, while the LDD consumes 32 mW. Small-signal gain and bandwidth are measured. A photo diode and laser diode are bonded to the chip on a test-printed circuit board. Electro-optical measurements show an error-free detection with a bit error rate of 10−12at 20 Gbit/s of the RX at and a 25 Gbit/s transmission of the LDD.


Author(s):  
X. Zhang ◽  
Y. Pan ◽  
T.T. Meek

Industrial microwave heating technology has emerged as a new ceramic processing technique. The unique advantages of fast sintering, high density, and improved materials properties makes it superior in certain respects to other processing methods. This work presents the structure characterization of a microwave sintered ceramic matrix composite.Commercial α-alumina powder A-16 (Alcoa) is chosen as the matrix material, β-silicon carbide whiskers (Third Millennium Technologies, Inc.) are used as the reinforcing element. The green samples consisted of 90 vol% Al2O3 powder and 10 vol% ultrasonically-dispersed SiC whiskers. The powder mixture is blended together, and then uniaxially pressed into a cylindrical pellet under a pressure of 230 MPa, which yields a 52% green density. The sintering experiments are carried out using an industry microwave system (Gober, Model S6F) which generates microwave radiation at 2.45 GHz with a maximum output power of 6 kW. The composites are sintered at two different temperatures (1550°C and 1650°C) with various isothermal processing time intervals ranging from 10 to 20 min.


Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 927-934
Author(s):  
Tao Song ◽  
Chao Liu ◽  
Hengxuan Zhu ◽  
Min Zeng ◽  
Jin Wang

Abstract Normal operation of gas turbines will be affected by deposition on turbine blades from particles mixed in fuels. This research shows that it is difficult to monitor the mass of the particles deposition on the wall surface in real time. With development of electronic technology, the antenna made of printed circuit board (PCB) has been widely used in many industrial fields. Microstrip antenna is first proposed for monitoring particles deposition to analyse the deposition law of the particles accumulated on the wall. The simulation software Computer Simulation Technology Microwave Studio (CST MWS) 2015 is used to conduct the optimization design of the PCB substrate antenna. It is found that the S11 of vivaldi antenna with arc gradient groove exhibits a monotonous increase with the increase of dielectric layer thickness, and this antenna is highly sensitive to the dielectric layer thickness. Moreover, a cold-state test is carried out by using atomized wax to simulate the deposition of pollutants. A relationship as a four number of times function is found between the capacitance and the deposited mass. These results provide an important reference for the mass detection of the particle deposition on the wall, and this method is suitable for other related engineering fields.


Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 508
Author(s):  
Kui You ◽  
Zihan Zhou ◽  
Chao Gao ◽  
Qiao Yang

Biochar is a kind of carbon-rich material formed by pyrolysis of biomass at high temperature in the absence or limitation of oxygen. It has abundant pore structure and a large surface area, which could be considered the beneficial characteristics for electrodes of microbial electrochemical systems. In this study, reed was used as the raw material of biochar and six biochar-based electrode materials were obtained by three methods, including one-step biochar cathodes (BC 800 and BC 700), biochar/polyethylene composite cathodes (BP 5:5 and BP 6:4), and biochar/polyaniline/hot-melt adhesive composite cathode (BPP 5:1:4 and BPP 4:1:5). The basic physical properties and electrochemical properties of the self-made biochar electrode materials were characterized. Selected biochar-based electrode materials were used as the cathode of sediment microbial electrochemical reactors. The reactor with pure biochar electrode (BC 800) achieves a maximum output power density of 9.15 ± 0.02 mW/m2, which increases the output power by nearly 80% compared with carbon felt. When using a biochar/polyaniline/hot-melt adhesive (BPP 5:1:4) composite cathode, the output power was increased by 2.33 times. Under the premise of ensuring the molding of the material, the higher the content of biochar, the better the electrochemical performance of the electrodes. The treatment of reed powder before pyrolysis is an important factor for the molding of biochar. The one-step molding biochar cathode had satisfactory performance in sediment microbial electrochemical systems. By exploring the biochar-based electrode, waste biomass could be reused, which is beneficial for the environment.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1272
Author(s):  
Zhihua Fan ◽  
Qinling Deng ◽  
Xiaoyu Ma ◽  
Shaolin Zhou

In recent decades, metasurfaces have emerged as an exotic and appealing group of nanophotonic devices for versatile wave regulation with deep subwavelength thickness facilitating compact integration. However, the ability to dynamically control the wave–matter interaction with external stimulus is highly desirable especially in such scenarios as integrated photonics and optoelectronics, since their performance in amplitude and phase control settle down once manufactured. Currently, available routes to construct active photonic devices include micro-electromechanical system (MEMS), semiconductors, liquid crystal, and phase change materials (PCMs)-integrated hybrid devices, etc. For the sake of compact integration and good compatibility with the mainstream complementary metal oxide semiconductor (CMOS) process for nanofabrication and device integration, the PCMs-based scheme stands out as a viable and promising candidate. Therefore, this review focuses on recent progresses on phase change metasurfaces with dynamic wave control (amplitude and phase or wavefront), and especially outlines those with continuous or quasi-continuous atoms in favor of optoelectronic integration.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 284
Author(s):  
Yihsiang Chiu ◽  
Chen Wang ◽  
Dan Gong ◽  
Nan Li ◽  
Shenglin Ma ◽  
...  

This paper presents a high-accuracy complementary metal oxide semiconductor (CMOS) driven ultrasonic ranging system based on air coupled aluminum nitride (AlN) based piezoelectric micromachined ultrasonic transducers (PMUTs) using time of flight (TOF). The mode shape and the time-frequency characteristics of PMUTs are simulated and analyzed. Two pieces of PMUTs with a frequency of 97 kHz and 96 kHz are applied. One is used to transmit and the other is used to receive ultrasonic waves. The Time to Digital Converter circuit (TDC), correlating the clock frequency with sound velocity, is utilized for range finding via TOF calculated from the system clock cycle. An application specific integrated circuit (ASIC) chip is designed and fabricated on a 0.18 μm CMOS process to acquire data from the PMUT. Compared to state of the art, the developed ranging system features a wide range and high accuracy, which allows to measure the range of 50 cm with an average error of 0.63 mm. AlN based PMUT is a promising candidate for an integrated portable ranging system.


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