大阪大学大学院工学研究科 機械工学専攻 知能機械学部門 革新的融合ウェットロボティクス領域

Japanese / English

Research

MEMS (Micro Electro Mechanical System) has been widely used, ranging from home appliances to automobiles. In recent years, there have been so many studies on downsizing and integration of “man-made machines”; not only semiconductor devices but also mechanical systems and chemical systems. Development in micro-fabrication technique and effort in reducing system size was followed by the rapid development of the MEMS technology. Those systems and devices are driven by external energy power source. Most of their fabrication process is based on “top-down approach”. However, this top-down approach generally needs a large-scale external system and has many issues regarding energy conversion efficiency, energy supply system, and sensitivity. We have demonstrated an environmentally robust hybrid robotic system that uses living components, called “Cellular Build Up Wet Nano Robotics”.

Several researches in utilizing artificial micro structure and artificial material have been reported, but research devices or systems using cells as the smallest function unit of organism are still unexplored field. In Morishima Laboratory, by reconstructing cells and living tissues, new bottom-up cell buildup approach and micro-life mechanical system were proposed. In this laboratory, wide range of research is actively carried out with bio-micro machine as the keyword, and several unique life machine systems have been published.

By the development in technology for high efficiency mass cell culture and mass production of device made possible by the development of multi scale cell manipulation system, such as in cell sheet engineering, new actuator principle based on living cell and sensor utilizing extrasensory capability of organism might be possible.

To realize soft micro-actuator utilizing living cells based on cardiomyocytes as its driving source, devices design and basic experiments were conducted. A novel bio-actuator possessing both mechanical and chemical function, and utilizing cells as materials was design, and operable mechano-bionic systems driven by chemical energy only was successfully developed. Although our group has already presented a bio-actuator using rat heart muscle cells, it is difficult to keep rat heart muscle cells contracting spontaneously without maintaining the culture conditions carefully. In contrast, insect cells are much robust over a range of culture conditions (temperature, osmotic pressure and pH) compared to mammalian cells. Therefore, insect cells are more practical for a hybrid wet robotic system, and they can be driven without precise environmental control.

From this point of view, to utilize robust biological components as a functional systems and self assembly process and their emergent functionality, and to build up such soft and wet machines will lead us an innovative fundamental change and produce a new principle and design to future man-made systems. Experimental results suggest the possibility of constructing an environmentally robust hybrid wet robotic system with living components and open up a new science and technology, bio-robotic approach, medical, environmental monitoring, agriculture and industrial application.

By the combination of the robotics-mechatronics, tissue engineering, ultra precise machining technology, regenerative medicine, and biomechanical field, achievement that was not possible with the development of only on a particular field, can be expected to be realized. With bio-MEMS, microfluidic control, and micro-fabrication as the fundamental technology, and active collaboration with research institutes and industry all over the world, we aim to create new values to the biomedical applications, health diagnosis, environmental analysis, biotechnology, pharmaceutical, and mobility business.

Research topics

1. MECHANICAL PROPERTIES OF CELL SHEETS

Cell sheet engineering has received considerable attention from researchers, for example, to regenerate function of impaired heart tissue or fabricate a layer of a pulsatile cardiac cell sheet by cardiac myocytes. To apply cell sheets in clinical application, it is important to confirm the mechanical properties of these cell sheets, for example, their contractile properties or elasticity. At this lab, we have developed a self-attachable fixture and a tensile test system to measure the mechanical properties of cell sheets. To confirm suitability of the fixture and test system, we measured mechanical properties of two different kinds of cultured cell sheets, C2C12 (cells mouse myoblast cells) and NIH-3T3 (3T3) cells (mouse fibroblast cells), and of the same kinds of sheets treated with cytochalasin-D. Using our system, we confirmed differences in mechanical properties these different cell sheets.

From Journal of Robotics and Mechatronics, Vol.25, No.4 pp. 603-610, 2013 "Measuring Mechanical Properties of Cell Sheets by a Tensile Test Using a Self-Attachable Fixture"

2. CONTROL OF TISSUE-BASED BIOACTUATORS

Live tissue bioactuators have been proposed as a new form of actuator. In this study, transgenic light-regulated dorsal vessel of Drosophila Melanogaster larva was used as a bioactuator. Feedback control of a bioactuated robotic arm using optical stimulation of the bioactuator and visual feedback of arm's end effector was performed. In this study, we investigated the response of the bioactuator to localized optical stimulation. The contraction displacement of bioactuator increased as total stimulated area of the bioactuator increased. Then, by varying total stimulated area of the bioactuator, we demonstrated position control of the robotic arm in a closed-loop system using visual feedback.

3. INSECT BIOFUEL CELL

Insects are extremely successful animals, living almost everywhere on the earth and their body fluid is rich in sugar. If electric power can be generated with their sugar, the insect will become an on-site power source. Our group has already reported a trehalase-glucose oxidase based BFC using trehalose of insect hemolymph. In this research, we proposed an iBFC with self-circulation system and developed the self-circulation system powered by the body fluid circulation in insect body. We also developed the AuNP-based BFC which oxidizes glucose by a catalytic reaction of AuNP in order to prevent the degradation of the output by deactivation of enzymes.

From Transducers 2013 "Gold Nanoparticle-based Biofuel Cell using Insect Body Fluid Circulation"

4. SINGLE-CELL PRINTING USING INKJET

Automation of piezoelectric inkjet-based single cell printing is the target of this study. Piezoelectric inkjet technology capability of high speed printing is the main advantage of this technology over other technologies. Therefore, this technology has gained attention in recent field of tissue engineering. Additionally, this technology was successfully developed for single cell handling. However, automation system for the single cell handling was not yet developed. In this study, utilizing open source image processing library, OpenCV, to process image of the inkjet head, automatic cell detection system was successfully developed. Finally, combining cell detection system and cell printing system, automation of single cell printing system with 98% successful ratio was successfully developed.

From RoboMec 2013 "Study in Automation of Piezoelectric Inkjet-based Single Cell Printing by Image Processing"

5. LABEL-FREE MAGNETIC 3D CELL ASSEMBLY

We have demonstrated a method to form and fuse spheroids on a microfluidic chip without cell labeling nor specific pattern of a microchannel using the magneto-Archimedes effect . Label-free magnetic cell manipulation became possible by adding a paramagnetic salt into culturing medium to enhance the diamagnetic property of the cells. Cells in the paramagnetic medium were aggregated ultra rapidly within a microchannel by applying a magnetic field. The spheroids were manipulated by changing the magnetic field. We also succeeded in fusing two different spheroids into a Janus spheroid on the same chip.

From Micro-TAS 2013 "On-Chip Formation and Fusion of Spheriods by Label-Free Magnetic Cell Manipulation"

6. 3D HANDLING OF CELLS USING MICROFLUIDICS

This paper proposed a Multiple Microfluidic Stream based Manipulation (MMSM) system for biological object using micro hydrodynamics and Lab on a Chip (LOC) technology. Our method can implement the function of micro manipulation and micro assembly of bio-objects without contact in an open space. Compared with other conventional bio-micro manipulation and assembly methods, this system is manipulating a micro object by controlling multiple microfluidic streams onto it from various directions. The advantage of this method is open space, multi-function, multi-scale, multi degree of freedom, and non-invasive three dimensions manipulation. These microfluidic streams are generated simultaneously from multiple orifices. By regulating the parameters of the microfluidic stream such as flow rates, position and number of operating orifices, the direction and velocity of the object can be controlled. To verify this principle, we designed an open space fluidic system for on-chip manipulation. The results presented in this paper showed that this MMSM has the capability for Micro Bio-manipulation.

From RoboMec 2013 "Multiple Microfluidic Stream based Manipulation System for 3D Cell Handling"