Development of nano-order monitoring system of plant and its environment using bio-speckles

本研究的目的是利用激光散斑光学干涉技术，如电子散斑图干涉法（ESPI）、统计干涉法（SI）、散斑差分法，开发一种高灵敏度的测量系统，以监测植物的各种状况和活动。与生长等生物活动有关的信息存在于植物表面的散射光场中。为了获得这些信息，我们应用了SI和ESPI。为了建立一种监测环境条件和环境污染对植物影响的光学方法，以臭氧作为空气污染的代表物质进行了实验。SI在测量物体膨胀方面达到了极高的灵敏度。利用SI技术，可以成功地测量植物叶片的生长速度，具有亚纳米级的灵敏度和秒级的高时间分辨率。结果表明，在0.12 ppm的臭氧暴露水平下，SI可以检测到植物生长的变化，这是日本发布光化学氧化剂警告的密度水平。由于目前还没有在纳米尺度上以如此高的时间分辨率观察植物行为的方法，通过本项目的研究，植物的各种有趣行为得到了新的揭示。一项新发现是植物的生长速度从来不是恒定的，而是一直在波动。结果表明，臭氧暴露前后植物生长速度波动的标准差之比与臭氧浓度有关。这个量可以得出一个空气污染及其对植物影响的数字。应用ESPI技术对植物的开花过程和地理特性进行了观察。实验证实了该方法观察植物对环境条件变化的适应性的有效性。这些光学方法也被应用于观察植物根系的生长。实验结果表明，由于SI具有较高的灵敏度，因此更适合于根这样薄的物体。少

Purpose of the present research is to develop a highly sensitive measurement system to monitor the various conditions and activities of plant based on optical interferometric techniques using laser speckle, such as electronic speckle pattern interferometry (ESPI), statistical interferometry (SI), speckle difference method. The information concerned with the biological activities such as growth lies in the scattered light field from the surface of the plant. To obtain such information, we have applied SI and ESPI. Aiming to establish an optical method to monitor the influences of environmental conditions and environmental pollution on the plants, experiments were conducted using ozone as a representative substance of air pollution. The SI has achieved extremely high sensitivity to measure the expansion of object. Using SI, the growth speed of the leaves of plants could be successfully measured with the sensitivity of subnano meter scale and with very high temporal resolution of second s … More cale. It was clearly demonstrated that SI could detect the change of the plant growth for the 0.12 ppm ozone exposure, which is the density level to issue a photochemical oxidant warning in Japan. Since there was no method to observe the behavior of plant with such a high temporal resolution at nano menter scale so far, various interesting behaviors of plants were newly revealed through the present research project. One of new discoveries is that the growth speed of the plant is never constant but fluctuating all the time. It was found that the ratio of the standard deviations of fluctuation in growth speed of plant before and after the ozone exposure depends on the ozone density. This quantity may lead to a figure for the air pollution and its influence on the plants.ESPI has applied to observe the blooming process and geotoropism of the plants. The validity of the method to observe the adaptation of plant for the change of environmental conditions was experimentally confirmed.Those optical methods have also applied to observe the growth of plant roots. As experimental results, it was shown that SI is more appropriate for such a thin object as root and because of its high sensitivity. Less