A mass sensing scheme with a two-warning function is proposed with a gradient-asymmetrically localized three-beam array (GALA), coupled with a variable length overhang, which is defined as an overhang of varying length along the transversal axis of the array. Compared with that of a symmetrically localized three-beam array (SLA), the amplitude change in the GALA prototype is observed to be significantly increased by about 100% with the localized first mode. While two intersections, appeared in three amplitude curves with respect to mass perturbation, are believed to be capable of playing early mass warning functions. These indicate that gradient-asymmetrical coupling, changing the mechanism of energy transfer, shows different energy localization characteristics from a symmetrical one. A localization factor of characterizing the inhomogeneity in energy localization is found to monotonically decrease from 3.10 to 1.70 with the gap between support and overhang while monotonically increasing from 2.75 to 3.10 with the width of overhang, and thus overlapped at 2.90. This implies that a very similar localized state with the same localization factor might be achieved by adjusting different overhang geometry. An optimal gradient angle of 7° with the highest amplitude change, corresponding to the maximum energy localization rate under a coupling ratio of 2.76, is further theoretically observed in GALA. The proposed scheme is believed to be applicable to detecting and warning of gas leak, dust pollution, harmful chemicals, and other applications.

A Gradient-Asymmetrically Localized Three-Beam Array for Mass Sensing With Warning

Effects of 5 MeV proton irradiation on 4H-SiC lateral pMOSFETs on-state characteristics

The effects of 10 MeV proton irradiation on the threshold voltage and gate oxide reliability of SiC MOSFET are investigated. The negative shift of the threshold voltage was observed after irradiation, and the magnitude of the shift is exclusively related to the fluence and not the drain
 voltage. Moreover, proton irradiation leads up to the degeneration of oxide reliability. Experiment and simulation results indicate that the shift of the threshold voltage is caused by the total ionizing dose effect. Due to the superior blocking capabilities of the SiC MOSFET, the electric
 field of gate oxide is almost unaffected by the voltage applied to the drain, so the drift of threshold voltage is only related to particle fluence. The single event effect is responsible for the degradation of gate oxide reliability. The single event effect induces a transient high electric
 field in the gate oxide, which generates defects and affects the reliability of the gate oxide.

The Influence of 10 MeV Proton Irradiation on Silicon Carbide Power Metal-Oxide-Semiconductor Field-Effect Transistor

Coupling element effect on anchor-limited Q in a synchronized oscillator with a π-shaped cantilever design

To realize the non-contact linear movement of microsphere which has the characteristics of high viscosity, small size, and fragile structure, an acoustic manipulation device based on bulk acoustic wave is proposed, fabricated and experimented in this paper. This manipulation device holds the merits of simple structure and the ability to manipulate large particles in micro scale. The finite element simulation method is used to determine the vibration mode of the device to form an appropriate standing wave acoustic field in the liquid. The acoustic pressure simulation of the liquid is carried out to study the distributions of the acoustic wave nodes. In the experiment, within a certain range, the farther the excitation frequency deviates from the resonance frequency, the microsphere is manipulated more stable. And the microsphere with large diameter has a faster motion velocity. The linear motion of different diameter microspheres from the container center to the circumference can be realized. The proposed non-contact manipulation device for the ICF capsule has broad application prospects in its non-destructive detection.

A Novel Disk-Shaped Microsphere Manipulation Device Based On Bulk Acoustic Wave


 Single Event Gate Rupture(SEGR) is one of the most severe problems that SiC MOSFETs experience in the space radiation environment. The influence of drain bias (VDS) and gate bias (VGS) on Single Event Gate Rupture was explored in this work using the fluctuation of leakage current when the device was irradiated at various biases. The source of leakage current is isolated and determined through testing, and the influence mechanisms of VGS and VDS effects on SEGR are further explored using TCAD simulation. The investigation demonstrates that while the drain bias can indirectly enhance the potential of SiC-side oxide, the gate bias can directly alter the potential of metal-side oxide during heavy ion irradiation. When gate bias and drain bias are combined, a strong electric field is generated in the gate oxide, resulting in SEGR in SiC MOSFETs. SEGR effect is a significant issue for SiC MOSFETs.

Study of heavy ion induced single event gate rupture effect in SiC MOSFETs

In light of the extreme environmental conditions of temperature and radiation faced by silicon carbide Metal–Oxide-Semiconductor Field-Effect Transistor (SiC MOSFETs) in aerospace electronic systems, the damage characteristics induced by high-temperature stress and Total Ionizing Dose (TID) radiation were compared. Moreover, the synergistic effect of temperature stress and TID on the performance of SiC MOSFETs was studied. The impact of temperature stress and radiation on threshold voltage and static power current is consistent; However, the degradation trend of on-resistance is opposite. The research shows that after temperature stress removal, the change in device performance parameters can be recovered. The total ionizing dose radiation can cause permanent damage to the device; In the environment of temperature stress and radiation, the increase of temperature can weaken or restrain part of radiation damage. 

Haonan Feng

Papers

The Influence of 10 MeV Proton Irradiation on Silicon Carbide Power Metal-Oxide-Semiconductor Field-Effect Transistor

Coupling element effect on anchor-limited Q in a synchronized oscillator with a π-shaped cantilever design

A Novel Disk-Shaped Microsphere Manipulation Device Based On Bulk Acoustic Wave

Study of heavy ion induced single event gate rupture effect in SiC MOSFETs

Temperature and total ionizing dose effects of SiC MOSFET and their synergistic characteristics