Electron microscope image capture with an oscilloscope

TL;DR

This video discusses how to capture digital images from a scanning electron microscope and the challenges of amplifying low signal levels.

Transcript

check out my scanning electron microscope collection this is the SEM that I built myself a couple years ago but the newest addition is this jeol J SMT 200 this was sent to me by Richard Anderson who rescued it from his University's trash heap and offered to send it to me if I paid for shipping from Sweden which I thought was a great deal so in this... Read More

Key Insights

• 🎮 The SEM in the video was rescued from a university's trash heap and sent to the creator from Sweden.
• 🈂️ Signal amplification is a challenge in electron microscopy, mainly due to shot noise caused by the discrete charge of electrons.
• 🌠 Different techniques, such as shooting more electrons at the sample and increasing electron energy, can enhance the signal.
• 🚄 Slowing down the scanning speed improves signal collection and allows for a higher number of electrons to be captured.
• ✋ Even with modern SEM models, capturing high-quality images requires significant time and careful signal handling.
• 😃 The video showcases various images captured with the SEM, including a MEMS gyroscope, a housefly's eye, and red blood cells.
• 🎮 The creator demonstrates how to capture and save the video signal data using an oscilloscope.

Questions & Answers

Q: How did the creator obtain the SEM featured in the video?

The SEM was sent to the creator by Richard Anderson, who rescued it from his University's trash heap and offered to send it if the creator paid for shipping from Sweden.

Q: Why is using a camera better than viewing the sample directly on the CRT?

A camera provides a better image because the electron microscope works by measuring emitted electrons from the sample, which has a very small signal. By using a camera, the signal can be amplified to create a more visible image.

Q: What is shot noise and why is it a problem in electron microscopy?

Shot noise is the result of the discrete charge of electrons, which limits the amplification of the signal. Even with advanced technology, shot noise remains a fundamental problem in capturing high-quality images with electron microscopes.

Q: How does slowing down the scanning speed improve signal collection?

Slowing down the scanning speed allows for more time at each point on the sample, resulting in the collection of a higher number of electrons. This trade-off between signal collection ability and time helps enhance the overall signal.

Summary & Key Takeaways

• The video shows a scanning electron microscope (SEM) built by the creator, which was sent from Sweden. It discusses the process of getting digital images off the SEM and into videos.

• The video highlights the challenges of capturing images from an electron microscope, specifically dealing with low signal levels and shot noise.

• The creator demonstrates different techniques to enhance the signal, including shooting more electrons at the sample, increasing energy in each electron, and slowing down the scanning speed for better signal collection.