Papers by Author: Zai Li Dong

Abstract: This paper introduces atomic force microscope (AFM) deposition method to fabricate nanostructures and nanodevices. Field emission theory is introduced in this paper, which provides theoretical explanation for AFM deposition. Dot matrixes are fabricated by AFM deposition on three different substrates, Si, Au and GaAs. Differences of deposition on the three substrates are discussed. AFM deposition has many practical applications. For example, AFM deposition can be used to solder nano components together to improve electrical properties of nanodevices. Besides nanosoldering, AFM deposition can also be used in fabrication of nanodevices. Thus AFM deposition is a valuable research field for future massive applications of nanodevices.

Abstract: Optically induced dielectrophoresis (ODEP) has been proved experimentally as a powerful method for efficiently manipulating some micro-scale, or even nano-scale objects. However, few ODEP platforms have been demonstrated towards the fully automatic wafer-scale manipulation and rapid fabrication of micro and nano sensors and devices. That would be of great significance to the application and industrialization of micro and nano materials. In this paper, an innovative ODEP platform for reconfigurable and automatic micro/nano-scale material manipulation is presented by combining microactuation and microvision analysis with ODEP technology. The ODEP chip consists of a typical photoconductive layer of amorphous silicon, which generates a nonuniform electric field at the light-illuminated region to induce dielectrophoretic (DEP) force for manipulating particles within the chip. A high resolution 3D motorized stage enables an accurate and rapid movement of the chip in wafer-scale. The microvision analysis program automatically recognizes the positions and sizes of randomly distributed particles and creates direct image patterns to manipulate the selected particles to form a predetermined pattern in predesired position. The programmed dynamic reconfigurable optical patterns provide increased functionality and versatility in particle manipulation. The patterning of polystyrene beads with different sizes is accomplished. This platform may be promising for rapid and wafer-scale fabrication of micro and nano sensors and devices, high-throughput bio-sample pretreatment and other applications requiring massively parallel manipulation.

Abstract: This paper proposed a preprocessing method of SWCNTs dispersion based on rinsing technology. With the assistance of SDS, SC and SDBS, this method adopted the ultrasonication oscillation technology to solve the problem of SWCNTs dispersion. In addition, it compared the effect of the three kinds of surfactants on SWCNTs dispersion under the same conditions. And AFM was applied in this experiment to scan and image the samples. The results showed that the solubility and adsorption efficiency of the surfactants had influence on the SWCNTs dispersion quality. Furthermore, the paper primarily and theoretically modeled and analyzed the experiment results from the aspect of the surfactants' hydrophilic and lipophilic structure.

Abstract: Single-wall carbon nanotubes are candidates for a number of building blocks in nanoscale electronics. With respect to the assembly of carbon nanotube field effect transistor, the dielectrophoresis technology is adopted, which assembles SWCNTs between the micro-electrodes, SWCNTs are affected by the electrophoretic force which is carried out by the related theoretical analysis in a nonuniform electric field. The driving electric field of dielectrophoresis is simulated by the comsol software. According to the simulation results, a number of the experiments are done. It turns out that the required experimental parameters of the efficient assembly of SWCNT were obtained. AFM scanning and electrical properties of SWCNTs show that the method can achieve the effective assembly of carbon nanotube field effect transistor. SWCNTs are driven in the microelectrode gap, having a good arrangement of uniform orientation and assembly results, and proportional to the arrangement density along the electrode width direction and the duration of DEP. Meanwhile, it also provides an effective method of assembly and manufacture for other one-dimensional nanomaterials assembly of nanoelectronic devices.