S-O3-3
BIOELECTRICS: Action of Plasma on a Living Body
バイオエレクトリクス：プラズマの生体相互作用
Hidenori Akiyama
秋山秀典
Kumamoto University, Graduate School of Science and Technology
2-39-1, Kurokami, Kumamoto 860-8555, Japan
熊本大学大学院自然科学研究科〒860-8555 熊本市黒髪2-39-1
Bioelectrics refers to the use of pulsed power, powerful pulsed electric or magnetic field for extremely
short periods of time, non-thermal plasmas in gases or liquids and shock waves, to give novel physicalstresses to biological cells, tissues and/or organisms as well as bacteria. Here, with the overview ofBioelectrics the plasma production in high pressure gas, liquid and supercritical fluid by pulsed power isdescribed, and also a recent development of Aoko treatment apparatus is described in detail.

1. What is Bioelectrics?
Bioelectrics refers to the use of pulsed power,
powerful pulsed electric or magnetic field for
extremely short periods of time, non-thermal
plasmas in gases or liquids and shock waves, togive novel physical stresses to biological cells,
tissues and/or organisms as well as bacteria.
Bioelectrics is an interdisciplinary academic fieldthat includes physics, chemistry, biology, medicalscience, agriculture, environmental, mechanical andelectrical engineering, and is expected to open up
new science and technology. For example,
nanosecond pulsed electric field can impart anunique stress on cells based on dielectric andelectrostatic effects to sub-cellular bio-moleculesand organelles, which is expected to lead to new
biological reactions. Also, intense pulsed electricfields can be used to kill bacterial spores in liquid.
Pulsed electric fields can have effects at themolecular level as well as be used to delivery
molecules or eliminate cancer cells. Atmosphericpressure, non-thermal plasmas produced by pulsed
power can be used not only for bacterial, viral andchemical decontamination, but also for medical
treatments such as wound healing. Plasmas can becreated even in liquid and used for the bacterial andchemical decontamination of water environment.
2. Plasma Production in High Pressure Gas,
Liquid and Supercritical Fluid by Pulsed Power
Plasmas are able to be produced in many media,
such as high pressure gases, liquid and supercriticalfluid, by using a pulsed power. The characteristics
of pulsed power are extremely high peak voltage
and current, and considerably shorter pulse width.
These characteristics cause discharge plasmas witha large volume even in high density media. The
plasmas produced in high density media give an

influence to animals, plants and bacteria. Especially,
the supercritical fluid has been used as a solvent for
extractions and chemical reactions, waste
processing and others. I think that the large volume
plasma produced in the supercritical fluid gives aliving body a strong effect, and these phenomena
becomes one of important fields of Bioelectrics.
Here, the basic phenomena of discharge plasmas
produced by pulsed power are presented in detail.

Fig.1. Discharge Plasmas in Supercritical Fluid

3. Recent Development of Aoko Treatment
Apparatus
The active multiplication of Aoko (Microcystis)in dam and lake is one of large environment
problems in the world. The Aoko looks like a green
water, and multiplies at high water temperature
with nutrition of nitrogen and phosphorus. We have
tried to treat Aoko by discharge plasmas in water.
Here, the recent development of Aoko treatment isdescribed in detail.

Fig.1. Aoko Treatment Apparatus