Grant amount：\3770000 （ Direct Cost: \2900000 、 Indirect Cost：\870000 ）

The purpose of this work was development of a measurement system for the surface property of thin liquid file, such as surface tension and viscosity, and generation of the scientific field in which the properties of thin liquid films were investigated especially. In this work, the oscillation of a micro droplet on glass plate is analyzed and the relations between the oscillation mode and surface tension and viscosity of liquid were obtained. In addition, a measurement system was developed in which the surface tension and viscosity were measured at one time and quickly even when the sample liquid had quite large viscosity. With this system, the dependence of the surface tension of melting polymer to temperature near the glass transition temperature was investigated.

researchmap

Grant amount：\3770000 （ Direct Cost: \2900000 、 Indirect Cost：\870000 ）

The purpose of this study is establish fundamental technologies of the micro driving system of fluid, which can be applied for the transportation devices in the micro-fluidics. The electro-magnetically spinning technique developed by us enables the remote manipulation of micro-mechanical elements, through the three dimensional control of the torque induced to the probe sphere. We successfully constructed an experimental system to deliver small probe sphere to an arbitrary position by driving the rolling motion of the probe. In addition by observing the relation between the driving torque and the motion of the probe, we succeeded in determining the local mechanical properties of the system. We found that the state of the solid-liquid interface is sensitive to the molecular adsorption and we are now extending the field of the system to the accurate detection of the chemical and biological functions.

researchmap

Grant amount：\19370000 （ Direct Cost: \14900000 、 Indirect Cost：\4470000 ）

The purpose of this study was to establish the fundamental techniques to fabricate microscopic functional devices through the generation and manipulation processes of the pico-litter liquid particles. We also tried to apply these techniques to the development of new measurement system of the fluid dynamics, such as the dynamic surface tension and rheology measurement in hyper shear rate region. First, we established the in-flight manipulation technique of the flying liquid particles using the Maxwell stress, which is the force induced by the difference between the di-electricity of the liquid and surrounding medium. The technique can be applied to the deflection of the trajectory of the flying particles, acceleration, and the excitation of the droplet oscillation in a noncontact manner. With these techniques, we constructed an in-flight fabrication process of the hybrid liquid particles and successfully made micro capsules, which can be employed for the drug delivery system.

researchmap

Grant amount：\18460000 （ Direct Cost: \14200000 、 Indirect Cost：\4260000 ）

Soft condensed materials, such as liquid crystal, gel, micelle and bio systems are characterized by its organized micro-structures, which is formed in a self assembling manner. These materials are also featured by its strong response to the outer stimulation such as the change of temperature and pressure, shear deformation, and the application of the electric/magnetic field. Recently, many investigations have been carried out to realize the fabrication of soft integrated devices by using the above soft condensed materials. The purpose of this study is to establish the nano-rheoloy engineering technique which observes the dynamic process of micro fluid droplet formed and undergoing various phase transition in the air. In the study, we developed a new technique to observe the pico-litter chemical reaction through the microscopic and high speed observation of the collision of micro particles. We succeeded in explaining the proceeding of the chemical reaction in terms of the diffusion of molecules in small chemical reactors.
We have also developed a new technique to fabricate a series of liquid particle with high reputation rate of 500,000 shots per our by using the spontaneous growth of the fluctuation in diameter in the one dimensional fluid system : a liquid jet continuously generated from a thin nozzle is modulated in its diameter by a piezo-driver. By observing the break-up phenomena of the fluid jet, we could successfully show that evolution in the shape of the jet provides us of the dynamic mechanical properties of the aqueous solution, such as surface tension and visco-elasticity. In conclusion, the technique developed by us in this project would be powerful tools to investigate the nanoscopic fluid physics.

researchmap

Grant amount：\3300000 （ Direct Cost: \3300000 ）

最近、申請者らはソフトな材料群の表面を解析するための電界誘起表面歪顕微鏡の着想を得た。これは試料表面に近づけた探針から生じるナノメートル程度の広がりを持つ局所電界によって材料を変形させ、その応答からナノレオロジー測定を行う、というものである。本研究ではこの着想を発展させ、液体をはじめとするソフトマテリアル表面をナノメートル分解能で観察する新規の手法開発を目指した。本年度は基板表面に塗布された厚みμm程度の薄膜についてその粘弾性及び表面張力を測定するシステムを構築した。本システムではあらかじめ基板表面に電圧印加が可能な微小電極が埋め込まれており、その上にコーティングされた薄膜材料の効果・乾燥過程を迅速に実時間で追跡することができる。さらにこの電極形状を変形することにより、薄膜の粘弾性の厚み方向分布を調べる手法についても検討を行いその可能性を検証した。
また本手法を水/油/界面活性剤系において実現されるような界面の相溶現象の測定に応用する試みを進めた。これらの系では相溶の臨界点近傍界面エネルギーが急速に減少する。応力制御型界面張力測定が可能な本手法ではこれらの系のエネルギー測定を高分解能で実現できる。この結果、沿うように伴う2次元臨界現象の臨界指数を精度よく求めることが可能になった。

researchmap