Single-event burnout hardening of planar power MOSFET with partially widened trench source

We present a single-event burnout（SEB） hardened planar power MOSFET with partially widened trench sources by three-dimensional（3 D） numerical simulation. The advantage of the proposed structure is that the work of the parasitic bipolar transistor inherited in the power MOSFET is suppressed effectively due to the elimination of the most sensitive region（P-well region below the N＋ source）. The simulation result shows that the proposed structure can enhance the SEB survivability significantly. The critical value of linear energy transfer（LET）,which indicates the maximum deposited energy on the device without SEB behavior, increases from 0.06 to0.7 p C/μm. The SEB threshold voltage increases to 120 V, which is 80% of the rated breakdown voltage. Meanwhile, the main parameter characteristics of the proposed structure remain similar with those of the conventional planar structure. Therefore, this structure offers a potential optimization path to planar power MOSFET with high SEB survivability for space and atmospheric applications.

Harvesting biomechanical energy in the walking by shoe based on liquid metal magnetohydrodynamics

A liquid metal magnetohydrodynamics generation system （LMMGS） was proposed and demonstrated in this paper for collecting parasitic power in shoe while walking. Unlike the conventional shoe-mounted human power harvesters that use solid coil and gear mechanism, the proposed system employs liquid metal （Ga62In25Sn13） as energy carrier, where no moving part is requested in magnetohydrodynamics generators （MHGs）. While walk- ing with the LMMGS, the foot alternately presses the two liquid metal pumps （LMPs） which are respectively placed in the front and rear of the sole. As a result, the liquid metal in the LMPs （LMP I and II） is extruded and flows through the MHGs （MHG I and II） in which electricity is produced. For a comparison, three types ofLMMGSs （LMMGS A, B and C） were built where all the parts are the same except for the LMPs. Furthermore, performances of these LMMGSs with different volume of injected liquid metal were tested respectively. Experimental results reveal that both the output voltage and power of the LMMGS increase with the volume of injected liquid metal and the size of the LMPs. In addition, a maximum output power of 80 mW is obtained by the LMMGS C with an efficiency of approximately 1.3%. Given its advantages of no side effect, light weight, small size and reliability, The LMMGS is well-suited for powering the wearable and implantable micro/nano device, such as wearable sensors, drug pumps and so on.