They Move! - Intracellular Motors

When one thinks of a motor, they often think of a car motor or perhaps an electric motor. Something big hulking machine that makes your car run or spins the beater of your KitchenAid™.  Something similar to this:

Boiling it down however, a motor is something that coverts some form of energy into mechanical energy, that is, movement. Simply, a motor is something that spins. When you remove the notion of a motor being a large electrically driven hunk of metal, all sorts of possibilities arise. Possibilities like tiny nano-sized motors that can go inside cells. Tiny motors, inside your body, inside your cells. And they look pretty cute (the video has no sound).

In collaboration with ESPCI Paris (a physics and chemistry engineering college), Tom Mallouk's research group has created tiny rods made of gold and ruthenium that can be manipulated both collaboratively (many rods together) and independently using ultrasonic waves (sound higher pitched than humans can hear) as propulsion and magnetic waves as steering. Even better, the power-density of the ultrasonics used with the rods is in line with that of medical imaging solutions we use today, so we know its safe. Previous versions of this budding technology were incompatible with biological systems as it used fuels that were hazardous to living cells. These new rods both work well within the cytoplasm of the cell and are nontoxic.

Light Microscope and Scanning Electron Microscope Images of the Nanometers 

Just seeing what these little rods can do gives you an idea of the wide range of applications for these new little critters. Take this video of a bunch of these rods working cooperatively to rotate a line of cells.

In one situation you could make the little rods go insane, blending the internals of the cell. If you were able to target cancer cells with these rods, you could absolutely obliterate the cells, killing the cancer.

On the complete other end of the spectrum, delicate control of the rods could help future scientists learn more about the internal workings of the cytoskeleton of the cell (the network of filaments and tubules that provide support and movement throughout the cell) by poking and prodding around in ways we never have been able to before. Delicate control could also diagnose and provide therapy for various diseases in a noninvasive fashion.

These little rods are not only 50 times thinner than a human hair; they're also 50 times more useful. The technology is still in the very preliminary stages, but progress is being made. Brain surgery in the future may consist of injecting these little rods into your body, having the rods be controlled to go up in your brain, fix whatever needs to be fixed, and then get peed out. That seems a lot better than getting your head cracked open. As long as they don't accidentally crank up the speed and blend your brain...  well that'd be awkward.

If you'd like to learn more about this subject, a PDF of one of his recent publications on the topic can be found here.

Evolved to Succeed

“One general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live and the weakest die.” - Charles Darwin, The Origin of Species

Natural selection and evolution leads to traits that promote the overall success of a species. Some adaptations that nature has developed over millions of years are so clever and advanced that it becomes more advantageous to rip-off ideas that nature came up with, rather than try to develop our own. This biological plagiarism is called biomimicry, and is becoming an ever more popular form of research. 

This biomimicry is a aspect of research that Dr. Tak-Sing Wong, assistant professor of mechanical and nuclear engineering, is focusing on. Named one of the 35 Innovators Under 35 by the MIT Technology Review, Tak-Sing Wong is researching biologically inspired surfaces here at Penn State.














One of his research projects takes cues from the wondrous pitcher plant. Pitcher plants grow in soil which lacks nutrients important for the plant's growth, and since they are still here today, you know they have developed a mechanism to get them around this barrier to survival. Pitcher plants have modified leaves that resemble pitchers that one could serve iced tea in. At the bottom of these pitchers is a pool of bacteria or enzymes which dissolves the unsuspecting insect prey, allowing the plant to absorb the critical nutrients that the soil lacks. One of the big issues that the pitcher plant had to overcome to become successful is how to keep the insect inside the plant after it falls in the pitcher.

Through copious generations of survival (and death of unsuccessful plants), the pitcher plant has developed an incredibly slippery surface, a surface that insects cannot grip onto, keeping them trapped inside the pitcher for digestion. Wong's laboratory has taken cues from the pitcher plant and has created an incredibly slippery surface by assembling a porous solid impregnated with a lubricant, creating a "stable, defect-free, inert "slippery" interface."



The surface, named SLIPS (Slippery Liquid-Infused Porous Surfaces) can repel pretty much any liquid or organism, allowing it to roll right off, as seen from this video taken from his lab. Many more examples of the surface's prowess can be found at the bottom of Wong's website.



Due to its ability to function in rather harsh conditions (high pressures, resisting icing, physical stressors), the surface has many applications, like in medical equipment to prevent the harboring of bacteria, on boats to prevent barnacle growth, or in liquid transport systems that undergo physical stress. Maybe coat your clothes with it to make that ketchup slide right off!

Tak-Sing Wong's lab is doing some fantastic stuff, so this might not be the last time you hear about him here. If you'd like to read a little bit more in depth on this particular project, the article that was published in Nature can be found here.

More than Calamari

The future is always envisioned as a world of wondrous gadgets and incredible foreign technologies. The path traveled to reach this point however, becomes a little bit fuzzier. People see the final destination, but do not often consider the painstaking process of research that goes into every facet of new technology. Here at Penn State, around 805 million dollars is put into research per year. Simply, Penn State is a very active research university. In this blog, I want to share some of the most interesting and promising research that is being done here at University Park. I want to share what makes Penn State so exciting while at the same time giving insight for those people interested in pursuing undergraduate research.

One of the most exciting fields of research right now (at least in my opinion) is materials science. Most of the material science labs are in the Millennium Science Complex, so you know it has to be cool. 

They don't put just any old research into a building like that.

Material science is all about developing new materials to improve the products that improve our lives. Take medical implants for example. Right now implants can deteriorate. Our bodies do not recognize them as friendly, which means not only do our bodies not put in the effort to upkeep them, they actively reject the foreign objects. This is where Melik Demirel's lab (and squid!) comes in.

Squid teeth have a very unique property in that they are self-healing in the presence of water (which isn't that hard to come by for a squid). Thanks to the wonder of genetic engineering, they are able to take the protein which enables this to occur, stick it in a bacteria, have the bacteria divide like bunnies, and then harvest as much of this protein that they want. Its like a little farm for protein. They then can take the protein and combine it in a two-part polymer that can be formed into whatever shape suits your fancy. But now when your application tears, just add water! This video from their lab demonstrates the polymer's abilities quite well.

Since our bodies are more than 50% water, medical implants could utilize this polymer to great effect. The lifespan of implants could be dramatically increased, reducing the number of invasive procedures an implant patient would have to go through. But this is just one application of this new polymer. There are endless possibilities for materials that self-heal with water. Demeril proposes its use in hard-to-reach cabling: "If one of the fiber-optic cables under the ocean breaks, the only way to fix it is to replace it. With this material, it would be possible to heal the cable and go on with operation, saving time and money."

So in the future, when you get a self healing medical implant that saves your life, thank the squid. And thank Penn State.