ELECTROSTATICS NEWSLETTER
January/February No.148
PRESIDENT’S MESSAGE
A CALL TO EDUCATORS
This President's Message is specifically addressed to those members, including me, who are in the academic community: universities, colleges, technical schools, and high schools. By qualifying the article in this way, I certainly don't mean that the scope of the article excludes the general membership. By all means, read on!
In my last message, I stressed the need for the ESA to reach out to individuals working on the cutting edge of research related to electrostatics: biotechnology, MEMS, and nano-technology. In this message, I'd like to make the case that we could be doing more to promote the importance of electrostatics to the curricula of engineering and science programs. Those of us who were trained as electrical engineers or physicists no double learned about electrostatics the old fashioned way. Solutions to Laplace's equation in three or more coordinate systems provided the central focus for the first of what was usually a two-semester course in electromagnetics. Vector calculus and partial differential equations were the entry tickets to an understanding of the material. Without them, a student would inevitably fall behind.
Vectors and "diffy-q's", as the students call them, are still very much an important part of an engineering or science education, and I am far from suggesting that we eliminate them from courses in electromagnetics. What I am suggesting is that they not become the central focus or a means unto themselves. Courses in electromagnetics, particularly those that study the electrostatic realm (called "quasi-statics" in some circles), should abound in case studies of applications. In my experience, nothing motivates a student more than seeing from the start how course material and concepts relate to the world they know. In preparation for this article, I surveyed the plethora of introductory electromagnetics textbooks sent to me for evaluation by various publishers. Out of a group of about twenty, only two of them included any examples of the use of electrostatics in the real world. One of those books, published in 1979 and now out of print, is a mathematically-oriented text that was excellent in the days when EE students could expect to take a two-course sequence in electromagnetics, but probably would not be used by time-stressed instructors constrained to teach all of electromagnetics - statics as well as dynamics - in one semester. Also, its numerous examples were relevant two decades ago, but do not include problems that one finds in research and industry today. The other is a more recent
text (1998) that uses, among other topics, electrophotography and ESD as real-world examples of electrostatics. (In this survey, I did not include the example-rich but specialized book, Fundamentals of Applied Electrostatics by Dr. Joseph Crowley. That text is really not intended for the common introductory course in electromagnetics.) The universal feature found in all books published after 1990 is the conspicuous absence of details about finding solutions to Laplace's equation. This topic is given a cursory or low-level treatment in all the texts that I surveyed.
What these authors realize is that today, detailed knowledge of vector calculus and how to obtain field solutions in other than the most basic geometries need no longer be part of a basic education in electrostatics. Numerous computer programs can do the job faster and more accurately, and these programs are the first choice of working engineers who must find real numbers when working on problems in science and industry. I am not suggesting that we exclude advanced solution methods and the more esoteric elements of vectors from the curriculum. Rather, I submit that topics beyond the very basics can be placed in optional electives for students who want to specialize in electromagnetics or electrostatics and may go on to write the next generation of field-simulation tools.
The modern world is rich in technology that relies on electrostatics. Indeed, each of us is affected by electrostatics most every day, whether we realize it or not. If you are reading this newsletter on paper, its words appear before you by way of some electrostatic process, be it photocopying or ink-jet printing. If you are reading it via computer, electrostatics also has played a role in bringing the print to your eyes, because your computer could not have been manufactured without relying on electrostatics and ESD charge mitigation. If you drove your car today, then electrostatic paint spraying help protect its body from the harsh winter elements or the salty air in warm ocean climates. Similarly, your car's airbag sensor acted as an electrostatic sentinel to help keep you safe. If you took medicine, then electrostatics may have had a role in its manufacture. The film in your camera, the tissue you used to wipe your nose, and maybe even the mop you used to wipe up a kitchen spill, were probably manufactured by processes that rely on creating or eliminating electrostatic charge. A biotechnologist will tell you that the very cells that keep you alive rely on electrostatics to function.
Let's shift electrostatics education away from its pure mathematical orientation and move it toward the applied by using examples from industry, technology, and modern research. Examples of the role of electrostatics in document production, biotechnology, MEMS, air pollution control, space exploration, manufacturing, and electronics provide a fertile ground in which to develop revitalized curricula in electromagnetics. The face of electrostatics has changed, and it up to us to help the curriculum keep up.
For the Friendly Society,
Mark Horenstein
ESA President
HEALING WEB
Spray-on skin could make scars a thing of the past A MAT of polymer fibres designed to help wounds heal could spell the end for traditional wound dressings, say British scientists. The fine web of fibres, which is sprayed on, lets wounds heal by encouraging the formation of a strong skin structure rather than weaker scar tissue.
When skin is punctured, the damage often destroys the weave-like structure of collagen that gives skin its strength. But when the body tries to patch up the wound, an evolutionary legacy means it acts in haste: in ancient times, if people's wounds did not heal quickly, they were likely to die. So instead of rebuilding the complex collagen weave as before, the body creates a quick fix by producing thin, aligned strips of collagen. When skin cells grow on this, they produce the pale, less flexible material we know as scar tissue, rather than normal skin. Now Electrosols, a biotechnology company based in Haslemere, Surrey, has developed a spray it believes could help wounds heal without scarring. The spray produces a fine web of biodegradable polymer fibres that collagen-making cells called fibroblasts can grow on. As more and more fibroblasts grow on the polymer webbing, they produce a regular collagen structure, much like that in normal skin. Electrosols researcher Ron Coffee believes that controlling the formation of collagen in this way will lead to normal skin growth instead of scarring. To make the spray, Coffee mixes ethanol and a biodegradable polymer-such as polylactic acid--in a small semiconducting container, and then gives it an electric charge by putting an electric field across the container. Because the wound is at a far lower electrical potential than the polymer, the solution is attracted to the skin surface and flies out through tiny nozzles, producing fine, light fibres, each of them 5 micrometres in diameter. The fibres have the same charge so they repel each other, making them regularly spaced. "What you get is like a spider's web," says Coffee, who is currently developing a hand-held version of the spray. It looks like a fat pen about 2.5 centimetres across and about 15 centimetres long, and could be used by paramedics or kept in first-aid kits, he says. But other researchers are more cautious about the spray's prospects.
"This initial polymer fibre mat wouldn't necessarily have any bearing on the final scar. Collagen is organised and reorganised continuously, and that's governed by a whole range of things," says Bruce Martin, a reconstructive surgeon at the University of Florida. "This sounds very sexy, but I wouldn't put any great faith in it until I'd seen it work in animal and human trials," he says.
Ian Sample
Humphrey Wong sent us the preceding article which he got from the online edition of New Scientist, January 8, 2000.
BALL LIGHTNING
The short article on "ball lightning" in the last issue of the Electrostatics Newsletter has prompted me to write in.
I am the current Technical Manager of Wolfson Electrostatics at the University of Southampton
and have been at the University since 1981. During this time I have visited countless industries across the world dealing with electrostatic problems ranging from factory fires to actors getting static shocks on the theatre stage. I have come across a number of electrostatic phenomena, which at first seemed puzzling, but on careful investigation could almost always be explained. I must say however that I had always questioned the existence of ball lightning. I'd heard about ball lightning at school when one of my fellow pupils who spent his childhood in South Africa recounted a tale of a glowing sphere entering the window of their farmhouse once thundery evening.
About a year ago, I was having an afternoon teabreak with one of my colleagues in the Wolfson lab, which is situated on the seventh floor of a tower block at the University. The skies were darkening and there was obviously a storm brewing up. As I gazed though the window overlooking Southampton docks I observed what appeared to me to be glowing welding sparks falling vertically from the sky. I saw about half a dozen of these and I must admit that at the time it didn't register to me as anything out of the ordinary. In fact, I attributed it to maintenance work on the exterior of the building on one of the upper floors. Some minutes later a full electrical storm developed and I thought nothing more of it.
The following day I read in the local newspaper (The Southampton Echo) that there had been numerous reports of ball lightning in the Southampton area the previous afternoon.
As a scientist and engineer, a number of questions immediately sprang to mind. Was what I witnessed that afternoon really ball lightning? Can this phenomenon take the form of "orange sparks" falling vertically out of the sky? (Apparently it can according to the various Internet sites on the subject). I have yet to come across an explanation for this phenomenon which I am satisfied with. Maybe some of the ESA members can email me with their views.
Graham Hearn
ELECTROSTATICS 2001
The Call for Papers and First Announcement have been published for the 9th International Conference on Electrostatics which is to be held May 29 to June 2, 2001 in Koscielisko-Zakopane, Poland. Authors who wish to present papers are asked to submit two copies of a one page abstract before April 15, 2000 to the Organizing Committee:
Juliusz B. Gajewski
Inst. of Heat Eng. & Fluid Mech. Phone: +48 71 320 3201
Technical University of Wroclaw Fax: +48 71 328 3818
50-370 Wroclaw, Poland Email: elst2001@itcmp.pwr.wroc.pl
Further information may be obtained from the Organizing Committee.
Interestingly, five of the eight featured introductory lectures will be delivered by ESA members. Namely, Adrian G. Bailey, G. S. Peter Castle, Thomas B. Jones, S. Edward Law and Gerard G. Touchard.
A SPECIAL OFFER FROM ELSEVIER TO ESA MEMBERS
Elsevier, publishers of The Journal of Electrostatics, have offered to provide individual subscriptions to any ESA member who wished to purchase one. The price will be $99 per year. Compared to the normal institutional price of $1063, this offer is something of a bargain.
The one requirement is that you agree to use your copies only for personal use and not sell them to or buy them for an institutional library, company reading room, or other multi-use commercial enterprise.
Subscriptions ordered will be completely voluntary and will be placed through the ESA. Orders will be taken starting in February and can be placed on-line over our Web site at www.electrostatics.org. Alternatively, you can submit your order by filling out a paper form that will appear in the next newsletter. You must be an ESA member to subscribe at this discount rate.
QUESTION
Is it time to hold a joint conference between the ESA and the Electrostatic Processes group of the IEEE Industry Applications Society? Your thoughts are welcome.
UPPER ATMOSPHERE FLASHES ON THE WEB
Red sprites are a brief optical flash in the middle and upper atmosphere caused by large cloud to ground lightning. The University of Alaska - Fairbanks has a site http://sprite.gi.alaska.edu/html /sprites.htm with information. The red sprites are related to other flashes known as blue jets and elves.
Glenn Schmieg
Anne S. Benninghoff sent us a copy of an article from the January 15, 2000 issue of Science News (Vol. 157) which described in some detail other work being done in the field of sprites. It contained several references which might be of interest to sprite fans, including:
Findings of Mark Stanley (Langmuir Lab) and Carl L. Siefring (Naval Research Lab) appear in the October 15, 1999 Geophysical Research Letters.
In the June 15, 1998 and the September 15, 1998 Geophysical Research Letters, Victor P. Pasko and colleagues at Stanford University presented computer simulations of electrical events in the mesosphere following a positive lightning stroke.