Friday, 30 September 2011

Osaka City Station Fountain Monument

So if you are walking through Osaka city you might see this video above.  It might display the time (not exactly a water clock which I will show in another post) but more like a water jet printer.  Jets of water print out an image and due to the surface tension of the water (72 dynes) it falls in a form that represents an image.  Physical nature meeting design makes for a fantastic monument.

Thursday, 29 September 2011

Top 5 Industries to Use Surface Tension Devices


I had a little hiatus.  In Helsinki the weather is changing and new studies have begun so a brief break was necessary.

Companies and scientists use surface tension devices (tensiometers) for a number of different applications.  Certain industries and fields are more likely to use surface tension measurements to make interesting discoveries.  Below are the top five industries / fields that use surface tension:

1) Detergent & Soap
So many surfactants new surfactants are made everyday for making detergents and soap better.  Different formulations to help in cleaning clothes, hard surfaces or our bodies rely on surface tension to get the correct wettability.  A static surface tension device especially one that  can do high throughput surface tension instrument can determine the critical micelle concentration (CMC).  The CMC will tell you how efficient the clothes or whatever you are washing will get clean.  Most detergents should be above the CMC and most people use soap in excess.  A proper balance can be achieved in the formulation by finding this point with a tensiometer. 

2) Ink. Look at your printer.  From an image on your computer screen different inks are flying from a piezoelectric crystal (a small hole) onto a material like paper, drying, changing, repeating.  The inks used today are a far cry from the first inks used in ancient China.  The static surface tension makes sure the inks are not running too much where the dynamic surface tension makes sure the inks will dry fast enough.  With different inks, faster printing processes and different substrates (different paper, metals, plastics) finding the proper formulation is a lot more complicated than before. An instrument that can measure both the static and dynamic surface tension quickly, reliably and easily is needed.

3) Drug Discovery.  Finding a good drug with high efficacy in today's world is ever more difficult and expensive.  Many drugs might be too hydrophobic or have the wrong shape to be absorbed into the body through membranes to reach a target molecule.  A surface tension instrument can help identify the problem compounds before they get to a clinical trial and people discover that 3 million dollars was wasted for a drug that cannot be absorbed.

4) Cosmetics.  Want to see the wettability and application of different surfactants that can help absorb on the stratum corneum or deeper layers of the skin?  A surface tension instrument is one of the few instruments that can do this.  The skin made up of many layers of lipids.  People's skin differs with age, race and gender so cosmetic manufacturers want to find the best products with good wettability for these different kinds of people.

5) Lipid research.  Lipids are such a schizophrenic molecule.  They are both water loving and water hating.  They can be found alone but when in groups they can organize faster than an Egyptian revolution.  The different shapes are difficult to characterize and study from micelles, bilayers, to things weird things like sponge phase or cubic phase.  To study lipids one of the simplest ways was to use a monolayer trough which was originally understood by fantastic civil scientists like Benjamin Franklin and Agnes Pockels (two people that I have written about previously).  Even though this is an old technique people still explore the properties of many different lipids.  To mix it up scientists might add some protein, DNA or even the odd virus. 

Thursday, 8 September 2011

Au Revoir....

J'aime parler Francais....but my French sucks but it is still better than my Finnish.  Since I like to write about surface tension and properties of liquids I was looking at this really cool typeface and I decided to repost it on my blog.  It is called Au Revoir from Russian Designer Ruslan Khasanov.   For me nature is beautiful and combining the physicochemical nuances with art makes it more outstanding.  His sublime typeface uses running ink and another one uses something like water to make beautiful typography.  I wonder what the surface tension is?

Tuesday, 6 September 2011

Kibron has a new website!

Our lab has some surface tension devices from Kibron (I may have mentioned it here).  Today I looked at their site and it is new.  Pretty nice.

Monday, 5 September 2011

A motor made out of thin films

Adding wires to liquid films

Last year, a group of physicists from Tehran made the discovery that motors can be made of nothing more than a thin film of water sitting in a cell bathed in two perpendicular electric fields. The unexpected result of this set up is that the water begins to rotate. If one divide the water into smaller cells and each rotates too.
Check out the videos from the team at the Sharif University of Technology in Tehran  a number of  fascinating videos of it in action

What is making the thin water move? 

Vlad Vladimirov at York University in the UK asked the same question and they delved into the hydrodynamics to work out why this water motor is working. The key turns out to be the scale on which the effect takes place.  Since it is only a thin film of water as you can see from the videos the electrical current and the surface tension allow it to rotate.  (Not sure if it is just the top film that is rotating or the whole body of water.  Also it probably depends on what kind of film they added.).  They say the flow is generated at the edge of the cell where the electric field crosses the  (dielectric) boundary between the water and the cell container. The change in field sets the water flowing along the boundary.  Crucially, this flow is opposite on the other side of the cell and this is what sets up the circular flow.

Vladimirov points out that this effect can only happen in a thin film of the dimensions that they used in Tehran where effects such as viscosity and friction play a large role in the dynamics. In larger bodies of water, these effects become insignificant and the rotation stops. So scale depends on this kind of motor so no seeing this in the ocean.  However, this might be very interesting for its use in microfluidic devices and for parties. 
Ref: Rotating Electrohydrodynamic Flow in a Suspended Liquid Film

Friday, 2 September 2011

The Gulf Oil Spill

With so much news in the world today it is tough to forget that very recently the gulf was covered in oil.   It has not fully recovered.  One researcher that is working around Mississippi thought that the the AquaPi might be a good idea to use to observe residual oil left in different places in the Gulf because of the portable size and reliability .  This device was used by oil companies to find residual oil at the refineries.    This infographic shows the different stages of the oil in the gulf and the physics of oil spills.

Thursday, 1 September 2011

Raindrop gif

This is what it was like in Helsinki yesterday.  From here it is impossible to see what a raindrop looks like but see my previous posts for a better explanation.