Artificial Insemination System by Male and Female Micro Robots
In the biomedical field, the precise operation is required to achieve cell injection and genome analysis. To enhance these technologies, the special instrument with higher accuracy can provide the solution to these requirement. Several sophisticated instruments have been developed and some of them are equipped with the advanced sensor and actuator. In the meantime, the micro robotics has the potential application to many fields such the biomedical engineering as well as micro-engineering. For these years, our group have developed many small robots for the application to the precision engineering. In this report, the unique artificial insemination system operated by male and female micro robots is proposed and the successful experimental results are described. The small robot, which is approximately 1 cubic inch, is composed of piezo element and electromagnet to move precisely with the manner of an inch worm. And one small robot has the micro pipette actuated by the micro pump while another one has the special micro capillary which can incubate the fertilized egg. In the exper iment , the egg and the spermatozoon of fish are implemented into the micro injector and the micro incubator on these small robots. Two small robots can navigate each other to inseminate by using acoustic, optical and mechanical touch trigger switch sensors and reactive based sequential manner. And the fertilized egg in the micro incubator was successfully hatched after two weeks later under the temperature and water condition control instrument. Artificial Insemination System by Male and Female Micro Robots
Automatic Surface Damage Exploring and Repairing System by Precise Micro Robots
In recent years, many types of micro robots and locomotion mechanisms have been developed as high precision positioning tools and opened new application in the filed of not only precision engineering but biochemical one. Particularly the piezo driven mechanisms can allow the excellent positioning resolution of nanometer level within an infinite workspace although the feedback properties with external sensors are required to improve the coordinate accuracy over the working area1). Also the micro robot has the potential performance for the application in the special environment such inpipe and in-chamber where it is difficult for the conventional mechanism to extend its arm. Surface investigation of the product and the facility with complex curved surface, in which small mechanical defect should cause the serious problem, needs much of efforts to do. Our group have developed many small robots with micro tools and sensors on the precise locomotion platform which is composed of piezo elements and electromagnets. Basic structure and performance were reported in the previous papers2). In this report, the newly developed micro robots which can explore on the target surface in order to find out the mechanical damages such as crack and defect, and propagate the acoustic signal in order to indicate the damage location by the passive resonator are described. And another one which has dual microphones to detect the acoustic signal and maneuver itself automatically to repair the crack automatically is also explained. As illustrated in Fig.1, these small robots can collaborate each other on the target to perform this unique task. This system can allow the low cost precise inspection and automatic repairing over night without any expensive facilities. 2. MICRO ROBOTS FOR SURFACE DAMAGE INSPECTION AND REPARATION 2.1 Micro robot with stylus on U type micro fork and acoustic resonator The micro robot which can explore on the target sample and detect the mechanical crack, and then propagate its acoustic signal by the Automatic Surface Damage Exploring and Repairing System by Precise Micro Robots
O2 constraints from Paleoproterozoic detrital pyrite and uraninite
Redox-sensitive detrital grains such as pyrite and uraninite in sedimentary successions provide one of the most conspicuous geological clues to a different composition of the Archean and early Paleoproterozoic atmosphere. Today, these minerals are rapidly chemically weathered within short transport distances. Prior to the rise of oxygen, low O2 concentrations allowed their survival in siliciclastic deposits with grain erosion tied only to physical transport processes. After the rise of oxygen, redox-sensitive detrital grains effectively vanish from the sedimentary record. To get a better understanding of the timing of this transition, we examined sandstones recorded in a scientifi c drill core from the South African 2.415 Ga Koegas Subgroup, a mixed siliciclastic and iron formation–bearing unit deposited on the western deltaic margin of the Kaapvaal craton in early Paleoproterozoic time. We observed detrital pyrite and uraninite grains throughout all investigated sandstone beds in the section, indicating the rise of oxygen is younger than 2.415 Ga. To better understand how observations of detrital pyrite and uraninite in sedimentary rocks can quantitatively constrain Earth surface redox conditions, we constructed a model of grain erosion from chemical weathering and physical abrasion to place an upper limit on ancient environmental O2 concentrations. Even conservative model calculations for deltaic depositional systems with suffi cient transport distances (approximately hundreds of kilometers) show that redox-sensitive detrital grains are remarkably sensitive to environmental O2 concentrations, and they constrain the Archean and early Paleoproterozoic atmosphere to have <3.2 × 10 –5 atm of molecular O2. These levels are lower than previously hypothesized for redox-sensitive detrital grains, but they are consistent with estimates made from other redox proxy data, including the anomalous fractionation of sulfur isotopes. The binary loss of detrital pyrite and uraninite from the sedimentary record coincident with the rise of oxygen indicates that atmospheric O2 concentrations rose substantially at this time and were never again suffi ciently low (<0.01 atm) to enable survival and preservation of these grains in short transport systems.