Xiao Yu

Bio: Xiao Yu is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Silicon & Etching (microfabrication). The author has an hindex of 5, co-authored 24 publications receiving 118 citations.

CMOS MEMS-based thermoelectric generator with an efficient heat dissipation path

Abstract: This paper presents a CMOS MEMS-based thermoelectric energy generator (TEG) device with an efficient heat dissipation path. For present CMOS MEMS-based thermoelectric generator devices, the output performance is greatly limited by the high thermal-contact resistance in the system. For the device proposed in the work, the silicon substrate is etched into two comb-shaped blocks thermally isolated from each other, which form the hot and cold sides. Thin-film-based thermal legs are densely located between the two blocks along the winding split line. Low internal thermal-contact resistance is achieved with the symmetrical thermal structure. When the TEG device is embedded between the heat source and heat sink, the heat loss can be well controlled with flat thermal-contact pads of the device. For a full device with 900 n/p-polysilicon thermocouples, the measured open-circuit voltage reaches as high as 146 mV K−1, and the power factor reaches almost five times higher value compared to the previously reported results. A test system integrated with a single device presents an open-circuit voltage of 110 mV K−1 when forcibly cooled by a Peltier cooler, or 26 mV K−1 when cooled by ambient air.

Top-down fabricated silicon-nanowire-based field-effect transistor device on a (111) silicon wafer.

Abstract: The unique anisotropic wet-etching mechanism of a (111) silicon wafer facilitates the highly controllable top-down fabrication of silicon nanowires (SiNWs) with conventional microfabrication technology. The fabrication process is compatible with the surface manufacturing technique, which is employed to build a nanowire-based field-effect transistor structure on the fabricated SiNW.

Method for preparing nano structure on surface of (111) silicon wafer

Abstract: The invention relates to a method for preparing a nano structure on a surface of a (111) silicon wafer, belonging to the technical field of nano. The invention is characterized in that a monocrystalline silicon nano wall structure or nano horn structure of which the characteristic dimension is on a nano level is prepared on the surface of a (111) silicon wafer by utilizing the anisotropic wet-process corrosive characteristic of the silicon material, or a self-restricting oxidation technique is combined to further prepare a monocrystalline silicon nanowire structure of which the cross section is in an inverted triangle shape. The invention has the advantage of simple technique, only relates to conventional photoetching, anisotropic wet-process etching mask manufacturing, corroding and etching techniques, can implement large-scale manufacture, and is a convenient micro/nano integration technology. The nano structure manufactured by the method provided by the invention can be used for researching properties (including mechanical, thermal, electric and other properties) of a low-dimension monocrystalline silicon material structure, can be used as a functional structure component of a sensor, and has application prospects.

Method for preparing nanometer structures from top to bottom on surfaces of (110) type silicon chips

Abstract: The invention relates to a method for preparing nanometer structures from top to bottom on the surfaces of (110) type silicon chips, which belongs to the technical field of nanometer and is characterized in that the anisotropy wet process corrosion characteristics of silicon materials are used for preparing monocrystalline silicon nanometer wall structures or nanometer corner structures with the characteristic dimension being nanometer level on the surfaces of the (110) silicon chips, or a self limitation oxidation process is combined for further preparing the monocrystalline silicon nanometer line structure with the cross section in a reverse triangular shape. The method has the advantages that the process is simple, only the conventional photoetching and the anisotropy wet process corrosion masking manufacture, corrosion and etching processes are adopted, the large-scale manufacture can be realized, and the method belongs to a convenient micro nanometer integrating process technology. The nanometer structure manufactured in the invention can be used for studying the structure properties of the low-dimension monocrystalline silicon materials, including the study of the mechanical property, the thermal property, the electric property and the like, can also be used as sensor function structure components and has the application prospects.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Micropower energy harvesting

Abstract: More than a decade of research in the field of thermal, motion, vibration and electromagnetic radiation energy harvesting has yielded increasing power output and smaller embodiments. Power management circuits for rectification and DC-DC conversion are becoming able to efficiently convert the power from these energy harvesters. This paper summarizes recent energy harvesting results and their power management circuits.

Review of Micro Thermoelectric Generator

Abstract: Used for thermal energy harvesting, thermoelectric generator (TEG) can convert heat into electricity directly. Structurally, the main part of TEG is the thermopile, which consists of thermocouples connected in series electrically and in parallel thermally. Benefiting from massive progress achieved in a microelectromechanical systems technology, micro TEG ( $\mu$ -TEG) with advantages of small volume and high output voltage has obtained attention in recent 20 years. The review gives a comprehensive survey of the development and current status of $\mu$ -TEG. First, the principle of operation is introduced and some key parameters used for characterizing the performance of $\mu$ -TEG are highlighted. Next, $\mu$ -TEGs are classified from the perspectives of structure, material, and fabrication technology. Then, almost all the relevant works are summarized for the convenience of comparison and reference. Summarized information includes the structure, material property, fabrication technology, output performance, and so on. This will provide readers with an overall evaluation of different studies and guide them in choosing the suitable $\mu$ -TEGs for their applications. In addition, the existing and potential applications of $\mu$ -TEG are shown, especially the applications in the Internet of things. Finally, we summarize the challenges encountered in improving the output power of $\mu$ -TEG and predicted that more researchers would focus their efforts on the flexible structure $\mu$ -TEG, and combination of $\mu$ -TEG and other energy harvestings. With the emergence of more low-power devices and the gradual improvement of ZT value of the thermoelectric material, $\mu$ -TEG is promising for applications in various fields. [2017-0610]