HV Output Research Articles

Bulk Electroporation for Intracellular Delivery Directly Driven by Mechanical Stimulus.

Electroporation (EP) is an effective and widely accepted intracellular delivery method for fundamental research and medical applications. Existing electroporation methods usually require a commercially available EP system or tailor-made high-voltage (HV, up to kV) power source and are complicated, expensive, harmful to the cells, and even dangerous to the operators. A triboelectric nanogenerator (TENG) is a highly studied device that can generate HV output with limited charges and ultrahigh internal impedance. Here, we developed a Bulk Electroporation System based on TENG (BEST). To maximize the load voltage of the TENG, a flowing EP unit with a capillary was designed as a resistive load to realize impedance matching. A low conductivity buffer was used to further match and assist cell electroporation. Besides, the electrical model and experiments on cells transfected with the BEST showed that the bulk electric field of the cell medium could reach up to 1 kV/cm, therefore resulting in a nearly 30 times increase of trans-membrane potential, thus largely improving transfection efficiency. Finally, using 40 kDa FITC-dextran, we showed that a delivery efficiency above 50% with a cell viability maintained over 90% can be achieved in HeLa cells. This work demonstrated the potential of TENG in the biomedical field as a naturally safe HV power source. It also provided a simple, alternative, and low-cost solution for EP research and related biomedicine applications.

Demonstration of Feeding Vehicle‐Integrated Photovoltaic‐Converted Energy into the High‐Voltage On‐Board Network of Practical Light Commercial Vehicles for Range Extension

The setting up of a practical electrically driven light commercial demonstration vehicle with integrated photovoltaics (PV) is reported. The demonstrator vehicle is equipped with 15 modules based on the crystalline Si/amorphous Si heterojunction technology. The nominal total peak power under standard testing conditions is 2180 Wp. Specifically, the PV‐converted energy is fed into the high‐voltage (HV; 400 V) board‐net for a utilization of the large capacity of the HV battery and thus for direct range extension. The demonstrator vehicle is equipped with irradiation, wind, temperature, magnetic, and global positioning system sensors. Irradiation and temperature as well as the energy flows from modules, maximum power point trackers (MPPTs), low‐voltage buffer battery to HV battery via DC/DC, and from the HV battery to the loads during an exemplarily test drive day (May 31, 2021) are monitored. The range extension obtained at this day on our test route (51° 59′ N, 9° 31′ E) was 36 km, the corresponding CO2 savings account for ≈2.3 kg. The chain efficiency of the electronic components from the input side of the MPPTs to the HV output side of the DC/DC was 68.6%, whereas the DC/DC itself has an average efficiency of 90%.

8-Channel Neural Stimulation ASIC for Epidural Visual Cortex Stimulation

This paper presents an 8-channel neural stimulator application-specific integrated circuit (ASIC) for biphasic stimulation of the visual cortex, fabricated in a 0.35[Formula: see text][Formula: see text]m AMS HV process. Each channel is composed of a standard SPI interface, an 8-bit current digital-to-analog converter (DAC) and 120[Formula: see text]V compliant HV output stage. Thus, it is possible to deliver to the tissue arbitrary current waveforms with amplitudes up to [Formula: see text]8.192[Formula: see text]mA with 32[Formula: see text][Formula: see text]A steps. The measured maximum differential nonlinearity (DNL) of the current output does not exceed 1.1 LSB. The on-board current reference provides the output current of 16[Formula: see text][Formula: see text]A with a very low temperature variation. The maximum anodic and cathodic current mismatch after calibration is 25[Formula: see text][Formula: see text]A. The measured interpulse leakage current does not exceed 60[Formula: see text]pA. The ASIC was also tested with the electrode–tissue model, which describes the PEDOT electrodes of 560[Formula: see text][Formula: see text]m diameter in the phosphate buffer saline (PBS). The measurement results approve the possibility to stimulate with arbitrary current amplitudes with frequencies up to 1.5[Formula: see text]kHz.

An area-efficient LDMOS-SCR ESD protection device for the I/O of power IC application

Lateral Double diffused Metal Oxide Semiconductor (LDMOS) transistors are widely used in HV output circuit and its Electrostatic Discharge (ESD) problem have been well studied. LDMOS embed Silicon Controlled Rectifier (LDMOS-SCR) can be used to improve LDMOS ESD robustness. In order to further enhance the ESD self-protection capability of LDMOS-SCR, a new device LDMOS-SCR with a floating P+implant region (FP-LDMOS-SCR) is proposed in this paper. Due to the floating P+implant region is placed near the drain end, It2 of the new FP-LDMOS-SCR device increases obviously, compared with traditional LDMOS and LDMOS-SCR devices. The FP-LDMOS-SCR′s It2 with one floating P+is 1.3A and that with two floating P+is 2.7A. The results of Technology Computer Aided Design (TCAD) simulations will be presented in this paper to help analysis the physical mechanism and observe the ESD behavior of the LDMOS-SCR. The proposed FP-LDMOS-SCR, same driver capability with LDMOS, can be applied in HV output circuit and also provide its ESD self-protection through shunted ESD stress to ground.

Improvement in transient piezoelectric responses of NDE transceivers using selective damping and tuning networks

NDE ultrasonic applications for quality control purposes, based on piezoelectric devices working as pulsed ultrasonic probes, usually include some tuning circuit either across the pulser output connectors or close to the piezoelectric probe electrodes. Classic criteria to determine tuning parameters in ultrasonic transducers do not perform very well in transient regime under the typical electrical conditions and peculiar output impedances of the required high-voltage pulsers. In most practical situations, the tuning values are manually adjusted in specific circuits for each NDE case, testing each channel of a multiprobe inspection system to find the best sensitivity. In this paper, the positive influences of certain selective damping and tuning networks on the time and frequency behaviors of NDE piezoelectric transceivers are analyzed in detail. Different waveforms and spectra of received ultrasonic signals are comparatively evaluated for different real tuning conditions, after passing through two ultrasonic processes linked in cascade: a transmitter of industrial type and a broad-band ultrasonic receiver. Piezoelectric transducer impedances, transduction transfer functions, and HV output spikes from a piezoelectrically loaded NDE pulser, are computed, to identify separately the influence of each stage. In order to improve amplitude and axial resolution in the received transient responses, relative contributions from emission and reception tuning networks are individually evaluated for a particular NDE two-stage piezoelectric channel. Also shown are the final experimental results relative to the ultrasonic test pulse and detected in a through-transmission NDE configuration, gradually improved by using distinct tuning levels.