Papers by Keyword: Orientation Control

Abstract: Orientation adjustment is an important issue in the micromanipulation of cells. A non-contact method based on a swirl for cell orientation control was introduced in this paper. The swirl is produced by a pair of opposite micro-fluids squirting from two parallel tubes. Cell orientation adjustment is realized by cells rotation due to swirl viscous drag, which drives cells to desired configurations. The appropriate distances between the end face of the two tubes and the distance between the axes of them are 1-3 times tube diameter for the cells rotating in the swirl central zone. Especially when the distances are kept double the cell diameter, cells rotate steadily round the swirl central point. By pulsating jetting, fluctuant micro-fluid are generated which make cell rotating a certain angle. Adjusting the pulse duration, pressure and jetting velocity, the cell rotation angle can be controlled which make orientation control more precisely. The method is valid for cells of different shapes and sizes. The effectiveness of the proposed non-contact method for cell configuration control was verified by experiments.

Abstract: This paper deals with an orientation control method for micro objects, which have a size in the order of 100 micro meters, by using a board stage that is vibrated in the natural frequencies of various vibration modes. Orientation control is important for manufacturing processes, such as the assembling of small parts. Since it is difficult to grip and to manipulate micro objects, a simple and reliable method is desired. In this paper, the vibration mode is used for generating different motions of the stage and for controlling the orientation of the objects on the stage. Since each vibration mode has a unique vibration motion, different motions can be selected by choosing the vibration frequency. In order to design the stage so that the objects turn toward target direction, Finite Element Method (FEM) analysis was applied. And, the designed vibration stage was fabricated using a stainless steel thin plate. Experimental results showed that the actual vibration is similar with the simulation results. As an example of the orientation control of the micro objects, some small electronics parts were tested and they could be turned toward the target directions.

Abstract: BaxSr1-xTiO3 (BST) thin films were deposited by modified CSD, in which partially hydrolyzed Ti-alkoxide was reacted with Ba-Sr precursor solution to form highly polymerized BST precursor solutions, leading to the better electrical properties of the resultant thin films. BST precursor solutions of 0.1 M were prepared to deposit BST thin layers of 17nm ~ 20nm for one dip-coating operation with different barium to strontium ratio of Ba/Sr = 90/10, 70/30 and 50/50. Modified CSD-derived BST thin films were deposited on a Si wafer with Pt electrode or CSD-derived LaNiO3 (LNO) seeding layer with preferred orientation. BST thin films exhibited ferroelectric or paraelectric properties, depending upon the Ba/Sr ratio. Better electrical properties for the BST thin films were observed on a LNO seeding layer. Maximum tunability of our BST film was 41 % at 1MHz.

Abstract: This paper describes the deposition of PZT/oxide electrode thin film capacitors on Si(100) substrate with a CSD (Chemical Solution Deposition). Highly (100)&(001)-oriented SRO/LNO electrode films with a perovskite structure were obtained by the annealing at 700 °C from a precursor solution of Sr and RuCl3·2H2O for SRO and from a precursor solution of La(NO3)3 and Ni(CH3COO)2 for LNO. In addition, highly (100)&(001)-oriented PZT/oxide electrode capacitor were deposited on SRO/LNO/Si substrate by annealing at 650 °C, showing a good ferroelectricity of Pr=22μC/cm2 and Ec=55 kV/cm. In addition, the resultant PZT/oxide electrode thin film capacitors exhibited no fatigue up to 108 switching cycles.

Abstract: Pr-substituted Bi4Ti3O12 (BPT, Bi4-xPrxTi3O12, x=0.1-0.4) polycrystalline thick films with a-/b-axes orientations and thickness of 2-3 μm were grown on sputter-grown IrO2 layers by chemical solution deposition method for developing lead-free piezoelectric film microdevices. Electric-field-induced strains measurements were performed by double-beam laser displacement meter and longitudinal strain of e=0.25 % under 400 kV/cm and piezoelectric coefficient d33=63 pm/V at 10 Hz were observed in BPT thick film of x=0.1 with a-/b-axes mixed orientations. The value of strain closely related to spontaneous polarization and monotonously decreased with increasing x. Microstructures of 3 μm-thick BPT films were fabricated by photolithography and dry etching processes with several tens micrometers in size.

Abstract: Nd-substituted Bi4Ti3O12 (BNT) polycrystalline thin films with preferred a-/b-axes orientations were grown on sputter-grown IrO2(101) layers by chemical solution deposition method. After optimizing the heat treatment conditions, insulating characters and ferroelectric properties in 250-nm-thick BNT thin films with a-/b-axes orientations were investigated at room temperature. Low leakage current density of J=10-7~10-8 A/cm2 at 100 kV/cm and fair value of remnant polarization (2Pr=31 μC/cm2 at 400 kV/cm) were measured even though the Bi2O2 blocking layer aligned parallel to the film normal.