Tuesday, September 27, 2011

Artsy science

I've been working on various kinds of microscopes for about 6 years now, and I've taken a lot of pictures.  A LOT of pictures.  Somewhere in the realm of thousands.  Most of them are of nanowires of varying populations and striping patterns, but a couple were of funny things that were strange anomalies (i.e. nanowire walls and nano-Doritos).  Some of my pictures looked pretty artsy.

All of those pictures have been completely blown out of the water by a picture I took today.  Grad student Justin and I were evaluating the extent to which plasma etching revealed gold electrodes by plating gold and observing it under our optical microscope.  I have no idea what kind of etching happened to give us this shape, but there it is, a millimeter-sized treble and bass clef, both illustrated in fractal gold:

Merry golden melodies!
Nothing about this is, of course, at all publishable, so I don't mind sharing it.  We still have no idea what happened.  It almost looks like strips of support electrode gold came up after plasma etching, but we aren't sure.  In any case, it makes for quite a cool picture.

Sunday, September 11, 2011

Small is beautiful!

I know, I haven't posted on here in a while. That's because life happened, aka my social life exploded. I'm no less in the lab, but I am less at home and contemplating blogging.

Still, I can't help but write about this topic. A couple of weeks ago, I had the privilege to hear Paul Weiss, the director of the California NanoSystems Institute (CNSI) at UCLA, give an ACS webinar entitled "Small Is Beautiful." Paul and I overlapped at Penn State before he made the move to California, and he is a very insightful and brilliant person whose mind is always thinking about the next big thing. "Small Is Beautiful" was about the role of nanoparticles and nanoscience in present and future technologies. There were numerous questions that went unanswered in the interest of time, and it just goes to show how much the public doesn't know about the nanoworld.

Then again, there is so much that nano researchers don't know about the nanoworld. We are just scratching the surface with studies of nanoparticle toxicity and nanoengineered electronics.  There is also the (large, looming) question of how we can control nanoparticle assembly and direct them to where we want.  So far, this has been explored by linking with DNA or electrical fields/electrofluidics, or just plain letting intermolecular forces do the work (references for all of these available on request), but it remains a very important field of study.  One thing that we can glean from these findings: locating and directly positioning a single nanoparticle?  Not so easy.

I, for one, miss working with nanoparticles. I used to work with nanowires that weren't exactly nano-sized:

I didn't take this picture, but it's a scanning electron microscope picture from our group.  Obtained from science.psu.edu.
Now I work with nanostructured microelectrodes.  Essentially, the structural size scale is the same, but now I'm dealing with things that aren't free-floating in solution.  The nanowires were electroplated on a solid scaffold, then released.  The microelectrodes are electroplated on a solid scaffold.... and that's it.  They have their advantages (namely, their ability to interface with electronics), but I miss the quicker reactivity imbued by free-floating particles.... not to mention the larger amount of redundancy.  I used to be able to make 1 billion nanowires at a time, whereas I can only make 20 microelectrodes now.

There is a certain allure of nanoparticles, especially when they're all colorful and pretty and they produce transmission electron micrographs that look like this:
From the Hamad-Schifferli group at MIT.  Image from MIT News.
Those are gold nanoparticles of varying shapes and sizes, and their colors change based on the shape and size of the particles.  Definitely possible optics applications there, as unlike dyes, nanoparticles don't photobleach or break down under light exposure.

I suppose I'm somewhat rambling, but my point is that small is indeed beautiful, and there is a lot about nanotechnology that needs to be investigated.  Being a nanoscientist is fun, because I never know what I'll get to look at under the electron microscope next!