This proposal describes a measurement method that measures chemical, biochemical, and physical dynamic phenomena occurring in materials, living organisms, and devices under actual use, operating, and manufacturing environments, and links these phenomena to elucidation of the functions of the measured objects. This method is called "operando measurement". Now, there is a strong demand for development of fuel cells and secondary batteries with improved performance being effective in preventing global warming, and catalytic materials promoting energy saving and low environmental impact. In response to the demand, operando measurement is attracting much attention because the method possibly elucidates the functions of the measured materials and devices. Operando measurement has already been applied to catalysts and battery materials, providing useful information that is qualitatively different from the static, cross-sectional information of materials and devices in a non-use or non-operating condition provided by conventional methods.

However, there are several problems with the present operando measurement. For example, the present measurement does not always reproduce the actual environment of the measured object. As a result, the results measured on the nano-scale structure of the measured object do not reflect the actual situation under its operation. The spatial and temporal resolutions are insufficient for elucidating the functions. The measurement and analysis processes are difficult for users who are not familiar with such a measurement. Due to these problems, we cannot fully elucidate the functions of the measured object utilizing the present method. Additionally, we are applying the measurement to only a limited range of research fields presently.

This proposal aims to solve the above problems in the present operando measurement, establishing the "next-generation" operando measurement. Here, we refer to the following as the next-generation operando measurement: an innovated method that provides enough information to directly approach the core of functions of the object, and expands the application areas beyond the present catalysts and batteries to other materials and devices, even living organisms.

In order to establish the next-generation operando measurement by solving the above problems, we will discuss the following four issues:

• ① Development of an optimal "model environment" matching the R&D needs which can produce experimental data to elucidate functions of the measured objects, and which also expands applications to wide range of materials and devices, particularly to biological tissues.
• ② Construction of a sophisticated measurement system and development of measurement / data science technologies that connect between different scales to measure and analyze highlycomplex hierarchical structures in materials, devices, and biological tissues on multiple temporal and spatial scales, elucidating the relationship between the structures and their functions.
• ③ Development of measurement instruments and technologies with high resolution (time, CRDS-FY2020-SP-07 Center for Research and Development Strategy, Japan Science and Technology Agency iii STRATEGIC PROPOSAL Innovation of dynamical measurement under operation to elucidate functions - Next-generation operando measurement - space, energy, etc.) to raise the level of existing technologies and to extract information on inside of materials, devices and biological tissues, and interfaces between materials.
• ④ Development of measurement technologies based on data science to achieve the nextgeneration operando measurement sooner by utilizing data science technologies to make measurement and analysis more advanced and efficient.

The following four measures are listed to solve the above issues in a coordinated manner:

• ❶ Interdisciplinary fusion and collaboration to develop new science and to solve social issues which enables advanced fusion of R&D in cutting-edge science and technology to deepen operando measurement and to expand its applicable range.
• ❷ Implementing measurement informatics to create a data science platform which enables us to utilize cutting-edge data science technologies in operando measurement.
• ❸ Training and securing human resources which include scientists capable of promoting interdisciplinary and collaborative research, and measurement experts with knowledge in information science.
• ❹ Development of measurement and analytical systems taking into account the usability of users which creates an environment in which users in a wide range of fields can effectively utilize state-of-the-art measurement technologies.

On the other hand, new measurement methods have always triggered new scientific discoveries. The next-generation operando measurement will create and develop new scientific fields driven by measurement techniques for heterogeneous, unstable, and transient complex systems. Looking back at the history of scientific discoveries in various fields, this new technique has the possibility to bring innovation and open up new science.