The Forefront of the Nature Interface System Research
KIYOSHI ITAO (Professor, The University of Tokyo; General Editor of Nature Interface)
The basic concept of nature interface was described in the inaugural issue. In this issue, I would like to describe the specific goals and application technologies of the nature interface system research.
Background of Research and Development
Wearable information equipment has been developed based on the research areas which Japan excels in, such as microsensor technologies and microenergy technologies, which have thrived, along with precision information equipment technologies. These technologies have already been used to make commercial products such as wrist-held computers, PHS terminals, super high-density hard disks, and optical disks. These technologies are the driving forces of current IT industries. Watch technologies, telephone technologies, and computer technologies are the three pillars of IT industries, as shown in Fig. 1. In the research stage of wearable information equipment, their development started in a work management system in factories by combining a camera, a wearable computer, and a healthcare system using an electrocardiography connected to a wearable computer. Such sensor terminals in various fields are getting a great deal of attention.
Information exchange on research activities on microsensor terminals takes place most actively at the "Wearable Information Devices Symposium," which has been held six times so far, and is sponsored by the Horological Institute of Japan.
Goals of Development in the Nature Interface System
A small terminal consisting of sensors, an energy source, a CPU, and wireless devices is called a "nature interfacer." This is a more advanced form of wearable equipment. The goal of this research is to place this terminal in a human body and a natural/artificial environment to collect information, so that various types of environments can be improved. The research and development of such sensor terminals will be the basis of medical welfare, and the monitoring of the natural environment. These sensor terminals will also be the basic modules in the future Internet, where the number of terminals is projected to be a few trillion. The development of the nature interfacer is indispensable for the promotion and penetration of information technologies in the 21st century.
To achieve technology which will enable nature interfacers to obtain data in a way similar to the five senses in humans, and which would imitate human judgement and memory are essential for realization of nature interfacers (Fig. 2). The technologies are categorized as hardware (devices) and software (algorithms). In the devices, the main elements are energy, sensors, communications, and processors. The algorithm varies in all kinds of different forms, depending on the objects to be studied.
Research Theme: Applied Research for the Human Environment
The development of a wearable information acquisition system and its application to healthcare is expected. The major feature of the system is that it include not only conventional sensors, such as an electrocardiograph and an accelerometer, but also newly developed sensors such as a muscle sound sensor, a mastication sensor, and a perspiration sensor, as well as a super high-density optical memory, and an energy source with charging capability using the energy given out by a human being (see Fig. 3). There are additional research themes using these technologies, such as modeling of the human recognition process, quantification of fatigue and amenity, and the development of an intelligent interface for a nature interfacer. Applications in the working environment are also foreseen: research to ensure the amenity and safety of an automobile driver, a plant maintenance worker or a dockyard worker and research on collaboration efficiency using a computer, for example.
Research Theme: Applied Research for the Natural Environment (Figs. 4 and 5)
The two main themes in applied research for the natural environment are the observation of wild animals and plants, and air diagnosis.
With regards to animal observation, the behavior of animals can be monitored in detail, by attaching a GPS or PHS terminal to them. In such a terminal, sensors for posture, temperature, and acceleration are installed on the animals. The feasibility of using the sensors is checked first, by making a prototype system using available devices. After that, ultra-small sensors will be built, using micromachining technologies.
In research on air diagnosis, a laser measurement system will be built for environmental microparticles (microparticles floating in the air and microparticles in the ground water), where heavy metals and chemicals float. By the miniaturization of the measurement system, and by using position detection technology by GPS, real time observation of the spatial distribution of SPM and pollen will become possible.
The research steps for an air diagnosis system are as follows.
An offline system will be developed first, in which the air is pumped and collected as a sample with place/time information. In the next step, a system in which sensors are changed to be wearable so that real time analysis followed by wireless data transmission can be performed is achieved. At the same time, existing fixed environment monitoring networks are linked together. Environmental forecasting will become possible by utilizing the data and by studying the movement of chemical materials and polluting materials in the environment.
Research Theme: Application Research to Artificial Environments
Several systems will be developed in this research field. An indoor position detecting system will be developed using in-premise PHS and wireless tags. This system will be used to achieve wireless communications in a place like a shipyard, where communication using a conventional cellular phone system is impossible.
In the next stage, new systems will be built, such as a system that displays the figures and data in real time, a system that collects and transmits data about a human being's position, perspiration and luminance, and a system that achieves real-time control of air conditioning and illumination. Furthermore, a system that diagnoses sounds and images of working machines remotely, and sends alarms remotely, will be developed.
In the last system, conventional microphones and cameras will be used as the sensors first. Microvibrators fabricated using micromachine technologies and a swinging microcamera will be used next. Using such a system, the monitoring of miniature parts for watch manufacturing, multiple fiber-optics assembly, and electronics devices soldering will become possible. Such monitoring has been difficult before.
As I have stated, the nature interfacers will be used in a wide range of applications, from massive manufacturing facilities for ships, aircraft, and automobiles, to precision manufacturing facilities for precision products. This research will contribute to database creation for distribution situations. It may also contribute to the research of safety and efficiency enhancement in transportation systems.
Technology Development Theme
Research on Sensors and Actuators (Figs. 7 and 8)
The nature interfacer is based on sensors that can deal with a large amount of data in a non-destructive way.
Image and sound data are obviously effective. Furthermore, the sensitivity of the sensors can be enhanced greatly, by enabling the devices to change their directions. To this end, a 10-mm diameter swinging camera using a CCD chip combined with a three-degree-of-freedom wobbling mechanism will be developed. An array of vibrators within 1 mm square in size will also be fabricated to collect acoustic and vibration data.
To describe the steps more specifically, a 50-mm square camera system for monitoring alpine flora will be developed, in which a conventional CCD and a three-degree-of-freedom wobbling mechanism is built first. The size of this camera system will be miniaturized to 10-mm diameter, by using a three-degree-of-freedom spherical actuator. Another camera of 5-mm diameter at the front tip for soldering inspection will also be built, using a conventional CCD and one-degree-of-freedom wobbling mirror. The camera system will be made applicable to inspection of soldering, high-density wring plates, fiber-optics assembly, and precision components by adding a microphone to the system. As an acoustic nature interfacer, an ultra-small vibration detection chip will be developed, combining a cantilever array, which has self-detection capability using PZT thin films, with a button shaped battery and FM transmission circuits.
Technology Development Theme
Research of Microenergy Sources
Wearable and outdoor sensing equipment requires an automatic power generator that absorbs the energy in the surroundings, and converts it to electric power. Figure 9 shows the required energy. Due to this requirement, the development of power generators such as the one using vibration energy (50-mm square, 20 mW), the one using walking movements (20-mm thick, 1 W), and the one using body warmth (coat type, 1 mW), would be necessary. A human body generates 100 W of power. A nature interfacer would function well if at least 0.1% of the generated power could be utilized. For this reason, power generation from a human body is an important research theme.
Technology Development Theme
Research on Communications Method
In the research themes mentioned above, further development and progress are expected in research areas such as a system that conveys information from nature to networks, protocols, study and design of wireless equipment and power systems, information carrying devices using the human body surface, information carrying devices using the human body as a transmission medium, and so on. We are also studying a wireless system using light as a communication medium, for use in factories and hospitals where electro-magnetic noises may cause troubles.
Nature interface technologies have been overviewed in this article. In the next issue, I would like to write more about the nature interface frontier.
For more details, please refer to the book, "Wearables in the 21st Century" (by Kiyoshi Itao, Kogyo Chosakai).