SEM images

I apologize such a long delay between my last post and now. I’ve been very busy in the studio as well as experimenting at the laboratory. I’m now on the last leg of my time at BLOS, with the deadline for my final installation on the BLOS campus vastly approaching.

A lot of wonderful things have happened since I’ve posted last, but it seems I will unfortunately not have time to share everything. However, I really wanted to share some recent images I created/took while using BLOS’ scanning electron microscope. Carlton Rauschenberg (a wonderfully warm and intelligent research associate and lab tech) and I prepared some samples of the coralline algae I had previously looked at under a much simpler standard microscope, as well as some etched copper and rope fibers.

For those of you who have never heard of scanning electron microscopy, I will do my best to briefly describe what that process is like. SEMs are typically used to look at very, very small things–think the scale of diatoms, algae cells, or on the large end of the spectrum insect appendages. Luckily the machine at BLOS was able to look at somewhat larger things, and then zoom up to the scale of nanometers. For perspective, there are 1000 micrometers in 1 millimeter, and 1000 nanometers in 1 micrometer. That’s 1,000,000 nanometers per 1 millimeter. So, there’s quite of bit of zooming to be done when looking at, for example, the pieces of etched copper I looked at.

The image is created by shooting a beam of electrons at a sample that has previously been sputter coated in gold. The gold coating helps reflective the electrons from the surface of your sample back in to a number of different detectors that do several things that frankly I do not quite understand. If your sample is insufficiently coated you will experience flare ups, or hot spots, while imaging your sample. This has to do with the organic matter causing the electrons to charge up, which in turn creates the bright, almost glowing spots that you will see in some of my images. This is typically not great, but I ended up enjoying some of those “accidents” due to their theatrical, disorienting effects on the images.

Once you’ve prepared your samples, you have to place them on a stage thats located underneath where the beam is shot from. The stage is recessed and closed shut under pressure, in order to create a vacuous environment. Once the machine is under a certain pressure, the beam is fired up, and so begins the process of slow and tedious refinement of your image. You are looking at a monitor, while operating several different variables (in the forms of dials and toggles), so there is a rough draft image, if you will, of what you’re looking at. However, you never really get a complete visual of the image you’re taking until you take it.

You slowly zoom and refine the image by manipulating what are called the stigmators, the aperture, and the focus. Now, what exactly those things are, or precisely what they do, I am still unsure off. The aperture seems quite obvious–it has to do with how that reflected beam is received once reflected off the surface of your sample. The stigmators, I believe, adjust the distortion on two axes…think astigmatism. For some reason the image can appear smeared in a certain direction, adjusting these properly will allow you to mitigate those effects. The focus is adjusted after all the other variables have been tweaked and in conjunction with the magnification. Magnifying in steps, while at each step refining the formerly mentioned variables, under stronger and stronger magnification, allows you to slowly bring forth–to use a printmaking term–a bullet proof image. There are many more variables involved of course, but those are the most apparent ones. Once you feel you have refined to seeming perfection, you can zoom in and out as desired without really having to adjust much from there on out. As you find a place and magnification that interests you, you slow the scan speed and or reduce noise. When you reduce the noise of the scan you’re also slowing the speed of the scan and increasing the overall average of images per scan cycle. Allowing more scans to be averaged into your scan cycle can potentially create a better image. However, for reasons beyond my understanding, sometimes it does not make a better image, and sometimes you simply slow your scan speed and never worry about noise reduction. As you slow your scan speed and/or increase noise reduction the image that appears on your monitor will become clearer and at higher resolution. It will also take longer to load as you do so. When it looks as though it’s reached its maximum potential (this can be tested by overshooting), you simply save the image. The image is saved in a designated file of your choice, which you can then open and view the image you’ve taken. Sometime’s your image is complete garbage and you have no idea why…I would imagine that as you familiarize yourself with the technical operating of the machine that lack of understanding of what went wrong slowly diminishes.

Okay, I have already gone on longer than I was hoping to. My apologies for rambling. This process as you might imagine is incredibly complicated and takes time to understand. These machines allow scientists and researchers alike to look at inconceivably tiny things. They are also amazing art making tools. If I had more time I’d spend it with this machine, because the potential for art/science overlapping is endless. The potential for simply art making and experimentation, perhaps even more so.

Take a look at the images below. Some have been annotated with magnification and scale, others have not.

Shappy029 Shappy033











SEM images