This review article outlines biosensor integrated circuits using CMOS technology. As typical CMOS-based biosensor integrated circuits, potentiometry, amperometry, impedimetry, and so on were introduced. In addition, recent topics of CMOS-based integrated circuits are also reviewed.

In this study, we report a biosensing method to analyze and monitor simply and easily biological phenomena such as DNA recognition events, antigen-antibody reaction and cell functions in vitro by use of a semiconductor device. As the most important point, we focus on a direct detection of ions or ionized molecules with charges, because most biological phenomena are related to ionic behaviors such as sodium or potassium ions through ion channel at cell membrane resulted from cell-cell communications, and biomolecules such as DNA molecules have intrinsic molecular charges. That is, the principle of semiconductor-based biosensing device contributes to directly detect biomolecular charges. Thus, the platform based on a semiconductor-based biosensor is suitable for a label-free and noninvasive biosensing detection device in the field of in vitro diagnosis (IVD).

This article reviews image sensor technologies for biomedical applications. First, technology trend of image sensors are briefly summarized. Next, image sensors for biomedical applications are classified into four categories; an attachment type in a conventional environment, a water-tight package type, a dish type and an implantable type. Examples of some of these types are demonstrated. Finally, summary and future trend are mentioned.

This paper reports on microfabrication technique for fabricating micro coils for MRI (Magnetic Resonance Imaging). The standing micro coils, the screw-shaped micro coils, the bicone-shaped micro coils, and the gradient micro coils were fabricated for high resolution MRI. We introduced the structures of micro coils and the fabrication process of these micro coils.

Recently, complex microstructures are required for microsystems with expanse of application fields. There is a limit in two-dimensional layer stacking method based on the conventional semiconductor manufacturing process because the processing process has been complicated with the processing microstructures. In this paper, a simple fabrication process using a three-dimensional UV lithography in combination with rotation and inclination of single mask is introduced. In addition, applications for bio-microsystems are shown in order to confirm the validity of the proposed fabrication process.

Being small is a major virtue for medical devices, which enables low-invasive surgery and long-term treatment and/or monitoring by being attached or implanted to the patients. Hence, micro/nano medical devices, which have been developed via micro/nano technologies, are absolutely promising. The author's group also has worked on several micro/nano medical devices, which include implantable artificial kidney and needle-type dry electrodes for electroencephalogram (EEG) measurement. Both devices exploit micro/nano technologies to exhibit unique characteristics. Though they are still preliminary, through the research, we found that “Jisso” technologies are mandatory. Jisso originates from a Japanese word whose meaning include wiring, sealing, packaging, and even system implementation. Jisso technologies are the technologies which can make the micro/nano medical devices truly practical. In this presentation, I would like to share the idea of Jisso technologies for micro/nano medical devices using the artificial kidney and the needle-type EEG dry electrodes as the examples.

Microsized cell-laden hydrogel blocks are attractive cellular building blocks for in vitro reconstruction of 3D macroscopic tissues in bottom-up tissue engineering techniques. This review introduces microfabrication and microfluidic formation methods of the cell-laden hydrogel blocks, and manipulation techniques to assemble them for construction of the 3D macroscopic tissues. Moreover, we show applicability of the cell-laden hydrogel blocks and the 3D macroscopic tissues to biological research and medical treatments.

In many countries facing the aged society, it is expected that the serious society problem like lonely death will be increasing. Therefore, a system watching over elder's life is very important. Then, we developed the system watching over elder's life using information about indoor ambient atmosphere changes. Indoor ambient atmosphere is changed by acted daily activities regardless of the age or sex of resident. Our system acquired such changes using 7 sensors (gas, temperature, humidity, brightness) and could recognize daily activities using information that extracted by observer. And, it could classify resident's daily life pattern using features that extracted by automatic feature extraction method from acquired ambient atmosphere changes. In this paper, at first, we describe an acquirement of indoor ambient atmosphere changes using multiple sensors and a classification of resident's daily activities. Next, we describe the method for detection of the information that related resident's daily activities from acquired indoor ambient atmosphere changes automatically, and the method for daily activity detection from integrated signal of multiple sensor signals. Finally, we describe result of classification of resident's daily life pattern using features extracted by automatic extraction method.

In this study, we have fabricated membranes which are composed of 2-layers and 4-layers Pb(Zr,Ti)O₃ thin films with internal electrodes by using sputtering depositions. Electrical and driving characteristics as ultrasonic transducers of these membranes are evaluated. By increasing number of layers, the static displacement is reduced. However, for the multi-layered membrane, the dynamic displacement became large because of the large mechanical Q factor in resonant vibration. The emitted sound pressure level and characteristics of the ultrasonic transducer are estimated.

This research reports thin films composition of vibrating film on capacitive micromachined ultrasonic transducers (CMUT) for ultrasonic diagnoses. The CMUT constitutes an electrostatically vibrating film, which is fabricated by deposition processes of SiO₂ and SiN films as insulator and TiN and Al films as top electrode on an Si substrate. The ultrasonic waves are transmitted by addition of AC voltage between the top electrode of vibrating film and the Si substrate, whereas the reflective ultrasonic wave are received with the vibrating film and converted to the electrical signals for ultrasonic diagnostic images. When the vibrating film is initially deformed by an internal stress of the stacked thin films, the transmitting strength of ultrasonic waves and the capacitance change by receiving reflective ultrasonic waves are not enough to achieve a high sensitivity. Thus, the thickness of SiO₂ and SiN films was analytically and experimentally determined to achieve the flat vibrating film. Accordingly, a 300-nm-thick SiO₂ film with a compressive stress of 150 MPa and a 1700-nm-thick SiN film with a tensile stress of 100 MPa were decided as one proper films composition. Also, the prototype CMUT can acquire an image of sponge simulated a test body.