MIT students can now test and probe fragile, microscopic electronic structures using a novel online lab that can be accessed from dorm rooms and other convenient locations 24 hours a day.
Although WebLab's focus is the study of microelectronic devices like transistors, the general idea could be applied to state-of-the-art labs in other fields, such as chemical engineering.
"If you can't come to the lab, the lab will come to you," said Jesus del Alamo, principal investigator for the project and a professor in the Department of Electrical Engineering and Computer Science.
Many subjects in science and engineering education do not include a laboratory experience because of the substantial cost, space and training associated with the required testing stations, Professor del Alamo said. As a result, students learn only by textbook examples.
Laboratory experiences, however, can substantially enhance educational effectiveness. Students get to use the real thing, poke at it and make observations on its actual behavior. They can also compare measured characteristics with theoretical predictions and reflect on discrepancies, limitations and design criteria. In addition, a hands-on interaction with a physical system allows curiosity-driven exploration and becomes a powerful motivator for students. As a result, students learn better.
"What's wonderful about WebLab is that it offers such enormous economies of scale, while also allowing for true hands-on experiments without the logistical shortcomings of traditional laboratories," says Professor del Alamo.
Microelectronics-device characterization was a natural candidate for remote access through the web, he said, because the devices are small, they can be measured very quickly and the result of the experiments is of an electrical nature.
Up to eight transistors or other devices can be tested on WebLab at any one time. "This allows WebLab to be deployed in different subjects simultaneously and it also provides redundancy against transistor blowup -- not a rare occurrence," Professor del Alamo said.
This past fall, WebLab was used in three concurrent courses by about 120 MIT students. One of these courses involved students who participated from Singapore as part of the Singapore-MIT Alliance. WebLab can be accessed from any computer connected to the Internet using a conventional web browser.
At its busiest hour last fall, WebLab handled 13 users running 99 different experiments, Professor del Alamo said. "This extrapolates to a minimum capacity of over 2,000 users per week and over 15,000 experiments per week." In addition, even at this busiest of times,the average total execution time for each job from the moment that it was received by the server was about 16 seconds. "More than 70 percent of all jobs were executed immediately after being received by the server, about 25 percent had to wait for one job to be finished, and 3 percent had two jobs ahead of them. Clearly the system as currently designed has plenty of spare capacity," he said
The response from students on anonymous feedback sheets has been encouraging. Said one, "I liked being able to work on this from the leisure of my room. I normally don't have time during the day to work on lab assignments and thus find myself going to labs late at night when being in the laboratory is the most unpleasant. Being able to sit at my computer and work on the problem made me much more apt to actually think about what was going on instead of just trying to get results so I could go home."
"I thought this was a very useful experience. It's often tough to go through a course like this where we deal with such microscopic elements and not be able to see any real data. This problem set allowed us to get some real data and do some real calculations on it," another student said.
A student from Singapore agreed. "This assignment is quite an interesting and eye-opening experience because we actually obtained the experimental data from a lab in MIT through the Internet. The advancement of technology in information transfer is really awesome."
WebLab also enables students to investigate technologies that are considered "too hot to handle" -- the types of things that intellectual property concerns would normally preempt.
Last fall, for the first time ever, MIT students were able to access and characterize the latest and fastest state-of-the-art microelectronics technology through a version of WebLab installed by Professor del Alamo's team at Compaq's Alpha Development Group in Shrewsbury. Students were able to take remote measurements in real time on semiconductor hardware with which Compaq's engineers are designing microprocessors. Students then downloaded and studied the data. As a result, they were able to compare the hottest technology with a more mature one available through the main WebLab at MIT.
"Through this exercise, students could appreciate the staggering progress that has taken place in microelectronics technology in the last 10 years. The educational payoffs are unprecedented," said Professor del Alamo.
Equipment for WebLab was donated by Agilent Technologies, Advanced Micro Devices and Intel. WebLab is a project of I-Campus, an alliance between academia and industry for cooperative research efforts in technology-enhanced education.
A version of this article appeared in MIT Tech Talk on March 14, 2001.