Biofilms have caused many problems, not only in the industrial fields, but also in our daily lives. Therefore, it is important for us to control them by evaluating them properly. There are many instrumental analytical methods available for evaluating formed biofilm qualitatively. These methods include the use of Raman spectroscopy and various microscopes (optical microscopes, confocal laser microscopes, scanning electron microscopes, transmission electron microscopes, atomic force microscopes, etc.). On the other hand, there are some biological methods, such as staining, gene analyses, etc. From the practical viewpoint, staining methods seem to be the best due to various reasons. Therefore, we focused on the staining method that used a crystal violet solution. In the previous study, we devised an evaluation process for biofilms using a color meter to analyze the various staining situations. However, this method was complicated and expensive for practical engineers. For this experiment, we investigated the process of using regular photos that were quantified without any instruments except for digitized cameras. Digitized cameras were used to compare the results. As a result, we confirmed that the absolute values were different for both cases, respectively. However, the tendency of changes was the same. Therefore, we plan to utilize the changes before and after biofilm formation as indicators for the future.

The blend education of e-learning and hands-on activity was carried out, using Metaverse. The topic was picked up, relating to radioactivity, nuclear safety education and STEM education. The students were six 5th and 6th graders in an elementary school. The lecture was given to them through the virtual class in Metaverse (Second Life). And then, the hands-on experiments relating to radioactivity were carried out in real life, lead and guided by the teacher in Second Life synchronistically and supported by the teacher in real life sometimes. The questionnaire given to each of students after the hands-on experiments showed very clearly that the project satisfied with the original goals very well, from both viewpoints of STEM education and nuclear safety education at early stage (pre secondary) levels. We concluded that the blend education worked well for STEM education to much extent

Problem Based Learning (PBL) is a powerful tool for engineering design education. On the other hand, STEM education at pre-college levels is important, particularly for engineering education, to increase and maintain a nation's industrial competitiveness. In this paper, virtual PBL in Second Life was carried out for third graders (18 year old students) in some national colleges of technology, Japan. At the beginning of the class, teachers proposed an ill-structured problem for students to solve, like one in real life. The problem was “design your own eco-cars through virtual discussion and make them by prim virtually”. Students as avatars discussed the problem in Second Life using microphones. They designed their own eco-cars using pens and tablets and made virtual cars with prims. After the project was completed, they evaluated their work by offline questionnaires and online talks in the virtual world. All of the results were examined from the viewpoints of the effectiveness for engineering design and STEM education