The following article appears in the journal JOM,
47 (9) (1995), pp. 13-17.

JOM is a publication of The Minerals, Metals & Materials Society

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A New Paradigm—Multi-User Scanning Electron Microscopy

L.S. Chumbley, M. Meyer, K. Fredrickson, and F.C. Laabs

A laboratory designed for teaching the operation of a scanning electron microscope (SEM) has been developed at Iowa State University. The laboratory was developed to enhance the education of undergraduate and graduate students in the use of the electron microscope by allowing more students to gain hands-on experience at operating an SEM. While the system was designed for teaching purposes, the concept of a multi-user SEM has clear applications for industry and research as well. For example, researchers will be able to conduct SEM investigations from their offices using desktop computers; live images can be acquired and displayed during staff meetings in a conference room; production engineers can view quality-control samples while on the production floor. In short, a multi-user SEM possesses enormous potential for a wide variety of applications.


The scanning electron microscope (SEM) has become one of the most widely utilized instruments for materials characterization. Given the overwhelming importance and widespread use of the SEM, it behooves universities and colleges with materials-oriented programs to provide instruction in the basic operation of the SEMs. However, the single-user nature of traditional SEM results in such instruction being time consuming, inefficient, and often boring to the students involved. Students experience little hands-on instruction since they must take turns operating the machine.

The single-user nature of traditional SEMs also affects the manner in which they are utilized in industrial or research settings, where access is typically restricted to a small number of individuals. This may be due to a number of factors. Examples include the lack of trained personnel or lack of time available to train large numbers of people, the cost associated with training since typically only one or two people can be trained at a time, the physical separation of the SEM from the potential users, the difficulty of mastering the instrument itself, and/or the desire to prevent damage to the instrument by allowing unqualified users to operate the machine. Single-user or restricted-user facilities are the norm in almost all cases. Such arrangements often prevent individual engineers and/or researchers from personally examining samples or checking the results of samples examined by technicians.

The problems associated with both scenarios can be overcome by adopting a new method for SEM instruction and operation, one that allows multiple users access to the instrument in a pseudo-parallel, rather than sequential, manner. This necessitates developing an SEM that gives multiple users complete and independent control of the SEM and allows them to access and analyze SEM images and data in a parallel manner.

A first step in developing such a system has been taken at Iowa State University, where a conventional SEM has been connected to a network of computer-based remote workstations to provide students with direct, interactive access to the SEM. Control of the microscope is achieved by means of a local-area network (LAN), which also allows the students access to image analysis software and x-ray energy-dispersive spectroscopy (EDS) capabilities. The results thus far have exceeded expectations, and it is evident that possible applications of such a network exist in both industrial and research areas.

Figure 1

Figure 1. Photograph of a multi-user SEM classroom. At this time, four remote stations are in operation with plans to expand to six.


The classroom is shown in Figure 1. Although somewhat dated with respect to newer personal computer-based instruments, the JEOL 6100 allows the most important operating parameters to be controlled remotely by the use of a serial RS-232 computer interface. The classroom consists of a series of remote workstations networked to a computer server, which, in turn, is connected to the JEOL 6100 SEM. All controls, functions, and features of the SEM made available by the manufacturer, as well as image and data analysis software, are available at each of the four workstations. The microscope image is carried to a television monitor at each remote station using an RS-170 video feed from the JEOL 6100 provided by the manufacturers, and hardcopy prints can be obtained using a thermal printer. A typical workstation is shown in Figure 2.

Figure 2

Figure 2. Photograph of a typical remote teaching station, consisting of a computer, video monitor, thermal printer, and joystick control. This station also contains a small camera for video conferencing.

The JEOL 6100 comes with a motorized stage as standard equipment. Operation of the stage is controlled by a joystick, with buttons provided to select the rate at which the joystick moves the stage and rotation of the stage. The circuitry of the stage was altered to include a switcher box and a series of additional joysticks (Figure 3). By use of the switcher box, the instructor can give each remote station control of x-y sample movement and rotation.

Figure 3

Figure 3. Close-up of a typical joystick control built at Iowa State University to mimic the microscope joystick and the switcherbox system.

The computer platform chosen for the project was the Apple Macintosh. This decision was based on a consideration of student familiarity with the Macintosh, its ease of operation, and the availability of inexpensive network and image analysis software. The Macintosh computer (Figure 4) operated by the instructor acts as a server for the network and contains a frame-grabber board, a card that provides four additional serial ports, and a 28,800 baud modem for off-site communication. The server is linked directly to the microscope via the RS-232 port and is linked to the remote stations via Ethernet (Figure 5). Commercially available network software allows interactive control, or remote monitoring, of any activity taking place on any screen. The EDS system used is also controlled by the Macintosh. The system uses a serial interface from the server connected to the pulse processor of the EDS detector to acquire and display spectra.

Figure 4

Figure 4. The main computer control station for the laboratory consists of an Apple Quadra equipped with 40 Mb of RAM, a 500 Mb hard drive, and boards that provided EDS control, Ethernet connection, frame-grabbing capabilities, a modem, and four additional serial ports. The station also holds hardware used in operating the EDS system.

Figure 5

Figure 5. Schematic showing the layout of the laboratory and the local area network used.

The SEM laboratory also contains a projection system that is interfaced to the SEM and the server computer. This allows the SEM and computer screens to be displayed on a large screen for teaching purposes. The instructor can choose which display to project by means of an infrared remote control. The projection video system allows the instructor to point out features present in the live microscope image without having to walk to each remote station, or interrupt an on-going analysis at any particular station.


The laboratory network operates using software called Timbuktu®. 1 This software allows two modes of operation—monitor or control. Under monitor, operators at remote stations can only view the action taking place on the screen of the server computer; control allows direct control, just as if the operator were personally seated at the server computer. In a typical laboratory, control of the microscope is passed from one station to the next, allowing each student equal time operating the microscope while the remaining students observe. Since all students are continually logged-in to the server, control of the microscope is passed by means of a simple click of the mouse. The instructor can always override any computer commands by using the console knobs on the microscope.

The microscope is controlled by a program called Scope,2 which was written at Iowa State University. Scope allows the control of various operating parameters on the microscope and has been designed to be adaptable to more advanced models or machines from different manufacturers. The main control screen from Scope is shown in Figure 6. The JEOL 6100 only allows limited access to the control parameters of the microscope, requiring selection of accelerating voltage, beam saturation, and all initial alignment steps to be done from the microscope console. However, through Scope students can change focus, magnification, and probe current, and have access to other options such as auto brightness and contrast, the text editor, the scan coils, and the shutter used to take photographs. Scope only resides on the network server and is only available to the student using Timbuktu in the control mode.

Figure 6

Figure 6. The console view from the program Scope developed at Iowa State University to control the microscope.

Once the students have selected a suitable area and obtained a satisfactory image, the image can be acquired using the frame grabber board available in each station's computer. Image analysis then can be performed using Image, a shareware program developed by the National Institutes of Health.3 This program allows students to analyze micrographs to determine factors such as particle size or phase percentages. A typical screen shot from the program Image is shown in Figure 7.

Figure 7

Figure 7. A typical screen from the program Image.

The EDS system in use is also controlled by the network server. By using acquisition software called Microplus®,4 the spectrometer can be controlled using Timbuktu in the same manner as Scope is used to control the SEM. Once a spectrum has been acquired, it can be saved to any remote station. A typical screen from this program is shown in Figure 8.

Figure 8

Figure 8. A typical screen from the program Microplus.

In addition to the control software discussed, a tutorial package has been written for the Macintosh to provide further information for the students.5 This package contains modules that cover various topics such as basic microscope design and operation, backscattered vs. secondary imaging, and x-ray analysis. Students can use this software to obtain a brief introduction to the specific concepts to be investigated and demonstrated in the laboratory or review principles studied in previous laboratories. A page from this package is shown in Figure 9.

Figure 9

Figure 9. A typical screen from the SEM tutorial program written at Iowa State University.

By having the image and EDS analysis software reside on each remote station, students not actively involved in operating the microscope can analyze or process the acquired data for inclusion in their respective reports while simultaneously viewing the current image on the SEM that is visible on the remote station television monitor. This allows parallel processing of the data by all students, creating more efficient laboratory instruction. Additionally, the tutorial package allows students at any time to review basic concepts they may not understand.

The combination of these software packages enables all students to be involved at all times when not actively operating the microscope. When control of the microscope is desired, it is achieved simply and quickly with the click of a mouse. Thus, instruction is enhanced and the productivity of the lab period is increased.


The most critical shortcoming of the interactive laboratory is the microscope itself, which limits the degree of computer control available to the operators from the remote stations. The lack of access to the alignment controls prevents students from receiving full instruction on the equipment; however, newer instruments that more fully integrate operation of the microscope into a personal computer environment are available and should be well suited for implementation of the multi-user concept.

Iowa State University possesses an extensive computer network system, providing Ethernet access to the Internet's World Wide Web and connectivity to almost any place on campus. This allows access to the SEM laboratory on a 24 hour basis from essentially any networked computer on or off campus. This flexibility is utilized in a number of ways. Students are able to access the network directly from home and do not have to return to the laboratory to retrieve data or images stored on the remote stations. The instructor is able to monitor and control the server from both office and home computers by using Timbuktu. Student operation of the server computer can be viewed and override commands issued if desired. The sample can be viewed over the Ethernet connection by acquiring the microscope image using the frame grabber board and Image shareware. Thus, the instructor can monitor student operation without being present in the classroom.

The disadvantage of using a network software control rather than a hardware control in order to operate the microscope is related to the response speed of the system. Although this is not a serious shortcoming, remote operation using Timbuktu is slower than direct operation of the microscope from each station via a dedicated line. A recent upgrade to Timbuktu Pro® has greatly increased the speed of the network, improving the operation of the network considerably; however, if an even faster response is desired, speed may be further increased by having Scope reside on each remote station. A direct connection of each station to the RS-232 port of microscope via a switcher box arrangement similar to that used for the joystick control enables the instructor to switch control between stations. This situation might be appropriate for a small classroom setting.

The great advantage of using software, however, is that it makes operation and control of the microscope possible from any location that possesses the necessary software. It is this flexibility that raises interesting possibilities for the extension of the multi-user concept to industry and research environments.


Since the software-controlled concept allows the SEM to be operated from any suitably equipped computer on the Internet, links have been established with the local high school to provide students in physics, biology, and chemistry with the opportunity to see a sample in near-live time from the high school classroom. Small digital cameras in the classroom and the SEM laboratory allow video conferencing between the high school students and the SEM operator. The Timbuktu network software allows high school students to observe the SEM image and EDS spectra collection on their computer screen. These initial results prove that the multi-user SEM concept can be extended from the laboratory to essentially any location.

As part of this project, a page is being developed for the World Wide Web that will allow interested persons to download various SEM images of insects, plants, and materials. Another planned feature will carry a video image of the SEM, allowing viewers to watch students and researchers as they conduct their investigations.

A multi-user SEM may have numerous applications in areas besides education. For example, we expect that the system could operate in a research facility. While a technician would still be responsible for inserting the sample into the microscope, individual scientists could access the SEM from their respective offices. The scientists could perform the actual investigation or simply monitor the results seen by the technician. The results could be viewed immediately by a whole team of researchers either in their offices or in a conference room setting. Control of the microscope could be passed between investigators quickly and simply, allowing different samples, or different regions of a single sample, to be viewed in turn. In any case, the results of the analysis would be known instantly, and pictures and data could quickly be incorporated into a document or transferred electronically to other researchers.

A similar arrangement could be considered in an industrial setting. Production and quality control personnel could be linked directly to the company SEM facility, allowing them to view images and examine samples without leaving their work areas. Potential problems identified by the SEM operator could immediately be communicated to engineers responsible for production. The engineer could examine the suspect part personally, pass the information and image on to other involved personnel, and take immediate steps to rectify any problems. Such an arrangement will speed information transfer and increase productivity.

There would be no need for extensive training in these scenarios since the software controls could be limited to simple stage movement and control of magnification and focus. Instruments are now on the market that allow computer control of these parameters; thus, there would be very little training involved for the user before they could take advantage of the most basic capabilities of the microscope. Any potential user could be easily taught the keyboard controls necessary to operate the microscope, obtain the necessary data, and pass it along to relevant personnel.

Another advantage is that time is not lost in transit to the location of the SEM since a computer screen and keyboard can be placed almost anywhere. In fact, the SEM need not even be at the plant site, but could be anywhere in the world that has access to the Internet.


While similar networks can be implemented very easily by almost any institution that has a suitable SEM and access to minimal computing support, the development of future microscopes and materials characterization laboratories holds the most promise for taking advantage of the multi-user SEM concept. Those purchasing new instruments need to consider the available computer facilities and networking capabilities at the proposed site of the SEM and include appropriate hardware and software acquisitions as part of the overall purchase plan. Microscope manufacturers need to be aware that state-of-the-art computer access and connectivity is desired by buyers. New microscopes should be designed and built to include built-in Ethernet capabilities and computer-based stage movement and microscope parameter control.

There is no barrier to the widespread adoption and usage of multi-user SEM microscopy that cannot be solved by careful planning and a willingness to adopt modern computer-based methods of operation.


Funding for this project was provided by the National Science Foundation as part of their Instrumentation and Laboratory Improvement Program grant number USE-925217, with Professors J.D. Verhoeven, M. Akinc, and S.W. Martin as coprincipal investigators. The SEM was acquired on a project funded by the Office of Naval Research with Mufit Akinc as the principal investigator. Additional funding for computer programming has been received from Engineering Computer Support Services of Iowa State University. The authors gratefully acknowledge the assistance of Chad Miller and Jeff Jensen in establishing and maintaining the computer network and in recommending and making hardware purchases. Mary B. Anderson is acknowledged for her development of the SEM tutorial package.


1. Software available from Farallon Computing of Alameda, CA.
2. Scope was written by K. Fredrickson and is available via ftp from (username "scope" and password "guest").
3. Image was written by Wayne Rasband at the U.S. National Institutes of Health and is available from the Internet by anonymous ftp from zippy.nimh.nih.gov or on floppy disk from NTIS, 5285 Port Royal Rd., Springfield, VA 22161, part number PB93-504868.
4. Software and hardware available from Dapple Systems of Sunnyvale, CA.
5. Software being written by Mary B. Anderson using Authorware,® available from Macromedia of San Francisco, CA.


L.S. Chumbley earned his Ph.D. in metallurgy at the University of Illinois in 1986. He is currently an associate professor at Iowa State University. Dr. Chumbley is also a member of TMS.

M. Meyer earned his Ph.D. in ceramic engineering at Iowa State University. He is currently a post-doctoral fellow at Ames Laboratory, Iowa State University. Dr. Meyer is also a member of TMS.

K. Fredrickson earned his B.S. in computer engineering at Iowa State University in 1994. He is currently a software engineer at MTS in Eden Prairie, Minnesota.

F.C. Laabs earned his M.S. in physics at Mankato State University in 1965. He is currently an associate metallurgist at Iowa State University.

For more information, contact Scott Chumbley, Ames Laboratory, Iowa State University, 214 Wilhelm, Ames, Iowa 50011; (515) 294-7903; fax (515) 294-4291; e-mail: chumbley@iastate.edu.

Copyright held by The Minerals, Metals & Materials Society, 1995

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