Speaker 1: Welcome to tech Stuff, a production from iHeartRadio. Hey there,
Speaker 1: and welcome to tech Stuff. I'm your host, Jonathan Strickland.
Speaker 1: I'm an executive producer with iHeartRadio. And how the tech
Speaker 1: are you? It is time for a classic episode of
Speaker 1: tech Stuff. This episode originally published way back on July sixth,
Speaker 1: twenty sixteen. Really, I probably should have published this one
Speaker 1: on Valentine's Day now that I look at the topic.
Speaker 1: The topic is how tech could make better chocolate. Let's listen.
Speaker 1: In so, a consulting firm working on behalf of Mars Incorporated,
Speaker 1: which is a giant candy company that makes a lot
Speaker 1: of different chocolate products. This consulting firm went to a
Speaker 1: group of physicists at Temple University, and physicist is one
Speaker 1: of those words I have difficulty pronouncing. I think I
Speaker 1: might just say scientists. Scientists at Temple University. Hey, that's
Speaker 1: way better. And these guys had developed a method to
Speaker 1: make crude oil flow more easily through pipes using electric fields.
Speaker 1: So the question that the consulting firm had was could
Speaker 1: you do the same thing you did for crude oil
Speaker 1: for chocolate? And here's a spoiler alert, yeah they could,
Speaker 1: but I want to talk more about what they did
Speaker 1: and how they did it because it's a really interesting story.
Speaker 1: So I'm going to go into a bit more detail
Speaker 1: about the physics and the technology behind the scientist solution
Speaker 1: for this problem. It's pretty cool, and a lot of
Speaker 1: it was stuff I had no idea about before I
Speaker 1: began to research the story. So today's episode is going
Speaker 1: to be about chocolate. It's going to be about viscous fluids,
Speaker 1: about electroreological fluids and how an electric field can change
Speaker 1: their fluidic properties, specifically viscosity. So yeah, this episode's going
Speaker 1: to be science heavy, but there's also chocolate, so stick around.
Speaker 1: You know, everyone loves chocolate. So let's get into the
Speaker 1: physics first. Now, fluid dynamics is pretty complicated, and also
Speaker 1: there's some stuff that's related to this that falls into
Speaker 1: the category of misinformation about viscosity. So I'll be talking
Speaker 1: a lot about not just the principles in general, but
Speaker 1: some specific myths that I would like to bust as
Speaker 1: some of my former coworkers used to do on a
Speaker 1: regular basis. So, first of all, viscosity is a property
Speaker 1: of fluids or semi fluids, and it can be described
Speaker 1: as a fluid's thickness or stickiness, and its resistance to
Speaker 1: flowing due to internal friction. More accurately, viscosity is a
Speaker 1: measure of the resistance of a fluid's deformation due to
Speaker 1: tensile or shear stress. Now, sheer stress is mechanical stress
Speaker 1: that's parallel to the surface of that substance. So you
Speaker 1: could think of sheer stress as it's not perpendicular. It's
Speaker 1: not like an impact, right, It's more of a tearing
Speaker 1: tenstyle stress is a pulling stress rather than a compression stress,
Speaker 1: So again, instead of compressing stuff closer together, it's about
Speaker 1: pulling stuff further apart. And water has a pretty low viscosity.
Speaker 1: Honey has a very high viscosity. So we actually measure
Speaker 1: viscosity in units called poises poises. Water at room temperature
Speaker 1: twenty degrees celsius or so has a viscosity of zero
Speaker 1: point zero one poises or acenti poise. In other words,
Speaker 1: a thick oil might have a viscosity of one point
Speaker 1: zero poise. Now we measure viscosity with a viscometer. I'm
Speaker 1: not making that up. It's actually the name of the
Speaker 1: tool used to measure fluid's viscosity. Now, typically we will
Speaker 1: call a liquid viscous if its viscosity is higher than
Speaker 1: that of waters, and if the viscosity is lower than
Speaker 1: that of waters, because water is not the least viscous
Speaker 1: material that we know of, if it has a lower viscosity,
Speaker 1: then water we call that fluid mobile. So some fluids
Speaker 1: are so viscous that they can actually seem to be
Speaker 1: a solid, And this leads us to that misinformation I
Speaker 1: was talking about. It's one of those things that I
Speaker 1: hear bandied about pretty well, not as frequently as it
Speaker 1: used to, but it's one of those mis understandings that
Speaker 1: gets passed around as fact every now and again. And
Speaker 1: that is the idea that glass is one of these fluids,
Speaker 1: that glass is actually a fluid that is so viscous
Speaker 1: that it appears to be a solid, And that is
Speaker 1: not true. Glass is not a very, very viscous fluid.
Speaker 1: It's a little more complicated than that. So here's the
Speaker 1: basic idea. People have noticed that if they look at
Speaker 1: windows and very old buildings like medieval churches, they see
Speaker 1: that the base of the window is thicker than the
Speaker 1: top of the window. And this has led some people
Speaker 1: to conclude to jump to a conclusion that the reason
Speaker 1: why the base is thicker than the top is that glass,
Speaker 1: over the course of centuries has been flowing downward, and
Speaker 1: that it's so slow that it's not detectable under normal situations.
Speaker 1: It's only over the course of centuries that you can
Speaker 1: see the difference. Here's the problem is that that's just
Speaker 1: not that's not the case. That's not true, it's not
Speaker 1: what's happening. If you look at the glass making approach
Speaker 1: in the Middle Ages, you'll see why there's a thicker
Speaker 1: part of the paine of glass. Glass was created generally
Speaker 1: speaking in the Middle Ages through something called the crown
Speaker 1: glass process. It's a pretty neat idea pretty neat way
Speaker 1: of making glass windows. Here's how it worked in general. First,
Speaker 1: you get your raw materials to make glass, and in
Speaker 1: the Middle Ages that was essentially sand and potash, and
Speaker 1: you mix it together and you melt them in a
Speaker 1: very hot furnace. Then you would get a glass blower
Speaker 1: with a pipe and they would get a roll out
Speaker 1: a lump of molten glass put on the pipe, blow
Speaker 1: out the glass, so they expand the glass outward before
Speaker 1: flattening it. So they don't just you know, create a
Speaker 1: globe of glass, They actually flatten it back out. Then,
Speaker 1: with the flat glass, which is still hot and still malleable,
Speaker 1: it hasn't cooled to the point where it is really solidified,
Speaker 1: you would put that on a disc, a spinning disc,
Speaker 1: and the disk spins around to draw out the glass
Speaker 1: to flatten it further. Sort of like how a pizza
Speaker 1: maker will toss and spin dough in the air in
Speaker 1: order to make that circular pizza. It's kind of similar
Speaker 1: to that. So the disk spins and the centripetal force,
Speaker 1: if you like, is pushing the glass outward toward the edges.
Speaker 1: So then once that's done, you would cut the glass
Speaker 1: into panes so that you could fit them in a window. Now,
Speaker 1: that would mean that when you would get anywhere close
Speaker 1: to where the edge of the glass was, the outer edge,
Speaker 1: because you put the glass on that disk and you
Speaker 1: spun it around, the outer edge was thicker than the
Speaker 1: rest of the glass, just because that's where the excess
Speaker 1: was accumulating as it was being pushed outward due to
Speaker 1: the spinning motion. So typically window makers would cut panes
Speaker 1: so that a thicker edge would only be on one
Speaker 1: side and they'd put that side at the bottom at
Speaker 1: the base of the window, so glass didn't flow to
Speaker 1: the base. Hundreds of years it started out like that.
Speaker 1: It was like that from the beginning. That being said,
Speaker 1: glass is a really interesting substance. It's what we would
Speaker 1: call an amorphous solid, so saying that it's a fluid
Speaker 1: or a liquid is not accurate. But it is an
Speaker 1: amorphous solid, which is a little hinky compared to other
Speaker 1: materials that you might be familiar with. So typically not everything,
Speaker 1: obviously metals and glass being exceptions, but a lot of
Speaker 1: solids have an ordered crystalline structure, so that means the
Speaker 1: molecules are organized in a pretty regular lattice. They form
Speaker 1: a nice repeating pattern that goes throughout the entire material.
Speaker 1: When you heat up this solid, those molecules start to
Speaker 1: shimmy and shake, some of the molecular bonds might start
Speaker 1: to break down a little bit, the bonds between one
Speaker 1: molecule and another. The essentially the crystalline order breaks down,
Speaker 1: and if you heat a solid beyond its melting point,
Speaker 1: the crystalline structure completely breaks down and molecules will begin
Speaker 1: to flow freely, or as freely as the viscosity of
Speaker 1: that fluid allows and there's a very clear delineation between
Speaker 1: the solid and liquid stages. You can see the difference
Speaker 1: molecularly from the way this substance looks when it's in
Speaker 1: solid form versus in liquid form, and we call that delineation,
Speaker 1: that border between the two the first order phase transition.
Speaker 1: It's obvious when you look at it from a microscopic standpoint.
Speaker 1: I mean it's obvious from a macroscopic standpoint two, because
Speaker 1: a solid behaves one way and a liquid behaves another way. Now,
Speaker 1: when you cool a liquid down, its viscosity tends to increase.
Speaker 1: If you introduce a nucleation site into the liquid, crystals
Speaker 1: can form and you get that nice solid structure again
Speaker 1: once you get down below what the melting point was.
Speaker 1: But glass doesn't do this. Glass doesn't form a crystalline structure.
Speaker 1: Glass's viscosity increases, so it does what other fluids do
Speaker 1: at that point. But since it doesn't crystallize, it solidifies
Speaker 1: in a different way. The molecules actually form an irregular arrangement,
Speaker 1: not that nice ordered structure that you see in other solids.
Speaker 1: But that irregular arrangement is still cohesive enough to maintain rigidity.
Speaker 1: So glass does become a solid, it's just not a
Speaker 1: crystalline solid. It's an amorphous solid. We'll be back with
Speaker 1: more about how technology could make better chocolate after these messages. Now,
Speaker 1: there's no first order phase transition here. It's not like
Speaker 1: if you looked at the liquid form of glass and
Speaker 1: the solid form of glass, you would a massive difference
Speaker 1: in the molecular structure. But there is a second order transition.
Speaker 1: Now that transition is a little more subtle than first
Speaker 1: order transitions. It involves the thermal expansion and heat capacity
Speaker 1: of a material, so it wouldn't be as obvious to
Speaker 1: casual observation on a microscopic level, but there would still
Speaker 1: be differences with the thermodynamics of the material, so we still
Speaker 1: would say the glass is a solid, not a liquid.
Speaker 1: All right, I'm done with glass now, I promise. I
Speaker 1: had to go on that little track just because it
Speaker 1: was related to the stuff I was talking about, and
Speaker 1: I get really irritated seeing that one myth passed around
Speaker 1: as fact. So now you know, if you ever go
Speaker 1: through a tour and the tour guide says and the
Speaker 1: reason that the windows are thicker at the bottom is
Speaker 1: because glass flows over the course of hundreds of years.
Speaker 1: You can raise your hand and say, well, actually and
Speaker 1: tell them Josh Clark sent because I don't want that
Speaker 1: kind of burden on me. I like being able to
Speaker 1: take tours. Anyway, Let's get back to viscosity in general. So,
Speaker 1: like I said earlier, viscosity is due to internal friction
Speaker 1: of a liquid. And you might think that that sounds weird,
Speaker 1: like how can a liquid have friction inside of it?
Speaker 1: But we're talking about liquid specifically that have like molecules,
Speaker 1: and those molecules can have a tendency to resist getting
Speaker 1: by each other. So some molecules are more resistant to
Speaker 1: slip and by each other than others. Or a liquid
Speaker 1: could actually have particles that are suspended in it. It could
Speaker 1: be a suspension, which is different than just a pure liquid.
Speaker 1: But if it's a suspension, it's got particles suspended within
Speaker 1: the liquid at some level of density, right, Like some
Speaker 1: may be a pretty weak suspension where you don't have
Speaker 1: a whole lot, but others could have a greater density
Speaker 1: of particles inside a suspension of fluid. Make chocolate bars, say,
Speaker 1: and you're laying out melted chocolate into the mold for
Speaker 1: the chocolate bars, and it clogs up, and you have
Speaker 1: to stop production and clean out the clog and get
Speaker 1: everything back up to temperature and start it all over again.
Speaker 1: It's time consuming and expensive when that happens. So one
Speaker 1: solution to preventing it from happening is dilute the cacao
Speaker 1: more so that those particles don't clump up as much
Speaker 1: because there's a less dense CACW component in the fluid.
Speaker 1: That essentially means replacing CaCO with something else, typically something
Speaker 1: that is less viscous, like that oil that fat essentially,
Speaker 1: so you usually add more fat to the recipe so
Speaker 1: you get the more fat but less cacw. However, it
Speaker 1: ends up flowing better and creates the chocolate bars that
Speaker 1: you want without creating the clogs. But it's not necessarily
Speaker 1: the best product you could create. It's just the most
Speaker 1: convenient upon the method of production. So that's where this
Speaker 1: alternative solution comes in. If you could change the shape
Speaker 1: of those cacal particles in the fluid so that they
Speaker 1: packed together more effectively, you would reduce that viscosity, that
Speaker 1: internal friction of the fluid. So imagine you've got one
Speaker 1: of those inflated rubber balls, like a kickball or something. Now,
Speaker 1: imagine that you're able to grab hold on either side
Speaker 1: of this ball and pull it outward so that you're
Speaker 1: elongating it. Now it would become a more of an
Speaker 1: oval shape, or as the researchers at Temple University called them,
Speaker 1: prolate spheroids. Now, the interesting thing about these prolate spheroids
Speaker 1: is if you align them in the direction of the
Speaker 1: flow of chocolate, you can pack more of them together.
Speaker 1: They have these elongated sides, and they will fit together
Speaker 1: much more snuggly. You can create chains of them, and
Speaker 1: chocolate would flow much more readily. But how do you
Speaker 1: change the shape of those cacal particles. What is it
Speaker 1: that you could do to make them actually assume a
Speaker 1: different shape than their natural globular ball like shape. This
Speaker 1: is where electric fields come in. We're going to talk
Speaker 1: about applying magnetic or electric fields to a fluid to
Speaker 1: change its viscosity. But first, this doesn't work with every fluid.
Speaker 1: Not every fluid reacts to electric fields and magnetic fields
Speaker 1: in a way that will alter its viscosity. But it
Speaker 1: does work in fluids that have certain non conducting or
Speaker 1: weakly conducting particles suspended in an electrically insulating fluid. Now
Speaker 1: we call this a special type of liquid electroreeological fluid
Speaker 1: electroheological fluids. That essentially means that when you apply an
Speaker 1: electric or magnetic field to such a fluid, it changes
Speaker 1: its viscosity. Sometimes we also call them smart fluids, but
Speaker 1: more about that in a bit. Now. Interestingly, the property
Speaker 1: was completely discovered by chance. There was an inventor named
Speaker 1: Willis Winslow who observed the effect in the nineteen forties,
Speaker 1: and he actually patented it in nineteen forty seven. Now,
Speaker 1: for this reason, we sometimes call this effect of changing
Speaker 1: an electroheological fluids viscosity the Winslow effect, And I'll mostly
Speaker 1: be using that term from here on out, because there's
Speaker 1: only so many times I'm going to be able to
Speaker 1: say electroreeological before my mouth just decides to rebel against
Speaker 1: the rest of me and march out the door. And
Speaker 1: as entertaining as that would be, I kind of need it. Well,
Speaker 1: we know that the candy man can make better chocolate,
Speaker 1: but how could tech make better chocolate? I guess we'll
Speaker 1: conclude that when we come back from these messages. All right,
Speaker 1: So Applying an electric or magnetic field to such a
Speaker 1: fluid changes that fluid's viscosity within melliseconds like it's practically instantaneous,
Speaker 1: And if you remove the field, the particles in the
Speaker 1: fluid will snap back to their original shape, to the
Speaker 1: fluid's viscosity will return to what it normally would be.
Speaker 1: So the change isn't permanent. It only persists as long
Speaker 1: as the respective field persists, which is super cool because
Speaker 1: you can do these temporary changes that are really useful
Speaker 1: in specific situations and then have it go back to
Speaker 1: normal and it's like it never happened in the first place.
Speaker 1: But one thing to keep in mind is the direction
Speaker 1: of the electric or magnetic field is critically important when
Speaker 1: you want to make a particular effect. So in the
Speaker 1: case of chocolate, if you apply the electric field perpendicular
Speaker 1: to the direction of flow, you will actually increase the
Speaker 1: viscosity of the chocolate. You will make it thicker, more
Speaker 1: like a gel. Melted chocolate will turn into this kind
Speaker 1: of thick gel. It'll otherwise have all the same properties
Speaker 1: that had before, but that viscosity will increase dramatically. However,
Speaker 1: if you were to apply that electric field in the
Speaker 1: direction of the flow of chocolate. Then you would decrease
Speaker 1: the viscosity of chocolate and it will flow more freely
Speaker 1: at that point. Now this makes some sense because imagine
Speaker 1: that you have these elongated ovals, these prolate spheroids. Right.
Speaker 1: If you stand them vertically, then you could imagine them
Speaker 1: slipping through a pipe very easily. If you laid them
Speaker 1: out horizontally, you could imagine them ending up like blocking
Speaker 1: pipe easily. Because it's like trying to fit a long
Speaker 1: stick through a narrow doorway. If you don't turn it
Speaker 1: the right way, you're just gonna hit against the door.
Speaker 1: This is making me think of my dog, Timbalt, who
Speaker 1: has done this on numerous occasions. He just he can't
Speaker 1: get it through his little doggy mind that he needs
Speaker 1: to turn the stick vertical in order to move it
Speaker 1: through a doorway. He just wants to charge ahead full
Speaker 1: steam with the stick horizontal. In many other ways, He's
Speaker 1: an intelligent dog, so we forgive him this lapse of judgment. Anyway,
Speaker 1: the chocolate on a molecular level is essentially the same thing.
Speaker 1: If you are applying this electric field perpendicular to the
Speaker 1: flow of chocolate, then you get this much thicker mixture.
Speaker 1: And an interesting side note, the electro rheological properties of
Speaker 1: chocolate aren't a new discovery, right. I mean, I covered
Speaker 1: this story for house Stuffworks now because there was a
Speaker 1: new application of this property with chocolate. But we actually
Speaker 1: knew that chocolate would react this way already, at least
Speaker 1: to the point of increasing the viscosity, because back in
Speaker 1: nineteen ninety six there was a Michigan State University grad
Speaker 1: student who observed the Winslow effect on chocolate. And his
Speaker 1: name is doctor Christopher R. Daubert, and as professor, doctor
Speaker 1: James Steph worked with him. They both conducted experiments on
Speaker 1: liquid chocolate and observed the Winslow effect. Now, in that experiment,
Speaker 1: Daubert was again increasing the viscosity, not decreasing it, so
Speaker 1: he was turning chocolate into that thicker gel. That the
Speaker 1: liquid chocolate into thick gel. It wasn't until recently that
Speaker 1: we saw someone try and do the opposite. So that
Speaker 1: brings us to the Temple University experiment. So you had
Speaker 1: these researchers. They had worked on crude oil and decreased
Speaker 1: the viscosity of crude oil, which is a huge thing
Speaker 1: for the oil industry to be able to move oil
Speaker 1: more effectively without the fear of clogs or viscosity screwing
Speaker 1: up things that had been planned ahead of time. They
Speaker 1: wanted to see if they could, in fact use a
Speaker 1: similar approach to have liquid chocolate move more smoothly through
Speaker 1: a system, so that manufacturers could save money by not
Speaker 1: having to worry about cleaning up clogs and shutting down
Speaker 1: production for maintenance. So they had to test this hypothesis
Speaker 1: that an electric field directed in the flow of liquid
Speaker 1: chocolate would reduce viscosity. So they built a cool chocolate
Speaker 1: zapping gadget. It's not really a zapper, it's a it's
Speaker 1: kind of not entirely accurate, but I like the idea
Speaker 1: of using electricity to zap chocolate to make it better.
Speaker 1: That's just an oversimplification of what happened, but that's okay.
Speaker 1: I'll explain to you what was actually going on. They
Speaker 1: built this thing where it starts with a bit of
Speaker 1: a melting chamber. You can just think of it as
Speaker 1: like a a pot. It could even be a glass vial. Really,
Speaker 1: it could just be any little container that can hold chocolate.
Speaker 1: They put the chocolate in the container, and they cover
Speaker 1: the container, sealing it shut. They added compressed nitrogen gas
Speaker 1: into the chamber simply really to just increase the pressure
Speaker 1: inside the chamber itself. The chamber was heated so that
Speaker 1: you had chocolate melting into a liquid. There was a
Speaker 1: therma couple in there to make sure that the temperature
Speaker 1: was correct so that the chocolate would not overheat or
Speaker 1: cool down so much that it becomes solid again. And
Speaker 1: then the base of this container was essentially a drain,
Speaker 1: so there's like a hole at the bottom of the
Speaker 1: container that liquid chocolate could flow through. Attached to that
Speaker 1: was a tube, and inside the tube they put a
Speaker 1: series of metal mesh screens, and the screens were what
Speaker 1: generated the electric field. They had electricity running to those
Speaker 1: screens and creating electric field that way in the direction
Speaker 1: of the flow of chocolate, so the chocolate would end
Speaker 1: up flowing very smoothly through the tube and didn't have
Speaker 1: any issues. At the other end, they had another vessel
Speaker 1: container that the liquid chocolate would flow into, it would
Speaker 1: cool down solidify. So once that liquid chocolate flowed through
Speaker 1: into the collecting vessel and once it was free of
Speaker 1: the electric field, the cacal particles they went back to
Speaker 1: their original shape immediately. Again, they didn't have to transform
Speaker 1: or anything. It wasn't a gradual process. They boop moved
Speaker 1: back into those globe shapes that they typically are in,
Speaker 1: and the chocolate cooled and solidified and was, to all
Speaker 1: intents and purposes, indistinguishable from the chocolate that was being
Speaker 1: fed through at the top at that top chamber. So
Speaker 1: they were able to reduce the viscosity of the flowing
Speaker 1: chocolate and to the point where it was no there
Speaker 1: were no issues of clogging, it was perfectly fine. So
Speaker 1: they were able to prove that their hypothesis was correct,
Speaker 1: that in fact, this electric field applied in this way
Speaker 1: would decrease chocolate's viscosity. Hooray. But there's more to it
Speaker 1: than that. So this experiment was not just a success.
Speaker 1: The researchers actually realized that it had a lot more
Speaker 1: implications than just having chocolate flow freely through a machine.
Speaker 1: That again, the reason why chocolate has such a relatively
Speaker 1: high fat content is to create that oily fluid to
Speaker 1: reduce viscosity, to have the cacao particles suspended within it
Speaker 1: at a density that's low enough so that you're not
Speaker 1: likely to clog up the machines. But if you use
Speaker 1: this approach, if you use the electric fields to reduce viscosity,
Speaker 1: you don't need as much oil or fat in your
Speaker 1: chocolate content. You could actually start with a recipe that
Speaker 1: has less fat in it, and the electric fields would
Speaker 1: take care of the viscosity problem, so you don't have
Speaker 1: to have as much fat there. That also means you
Speaker 1: could have more cacal in your mixture. It could be
Speaker 1: a higher proportion of the overall recipe. So they found
Speaker 1: that they could reduce the fat content in certain types
Speaker 1: of chocolate by as much as twenty percent and still
Speaker 1: have no negative impact on the fluid's viscosity. Now, it
Speaker 1: depends on what type of chocolate they were using. They
Speaker 1: were actually using name brand chocolates, you know, like chocolate bars.
Speaker 1: They would try different types and depending on the type,
Speaker 1: they could actually end up removing up to twenty percent
Speaker 1: of the fat in the mixture and still have the
Speaker 1: chocolate flow without any problems. And beyond that, the researchers
Speaker 1: said that people who are tasting the chocolate afterward, because
Speaker 1: keep in mind, other than the fact that there was
Speaker 1: less fat in it, there was really no difference between
Speaker 1: the original chocolate and the end result. They said that
Speaker 1: the end result chocolate actually tasted better to them. He said,
Speaker 1: I had a more intense cacw flavor. It was more
Speaker 1: chocolatey than the original chocolate. Now that could be just subjective,
Speaker 1: or it could be purely psychological, but it's not outside
Speaker 1: the realm of possibility that by increasing the proportion of
Speaker 1: chocolate of cacao in your mixture because you've removed some
Speaker 1: of the fat, so you've got more cacal per unit
Speaker 1: of chocolate than you would previously, that you would also
Speaker 1: affect the taste. It is entirely possible that that is true.
Speaker 1: It hasn't really been tested on a scientific level. It's
Speaker 1: mostly people saying, hmm, this tastes really good. Also, I
Speaker 1: should mention this is not the same as fat free chocolate.
Speaker 1: Fat free chocolate is essentially using some different type of
Speaker 1: fluid other than oil to suspend cacal particles. So fat
Speaker 1: free chocolate has that particular weird taste. It's not the
Speaker 1: same as the stuff that Temple University was producing. So
Speaker 1: I just want to clear that up. It's not like
Speaker 1: you would take a bite of a brand new chocolate
Speaker 1: bar that was made using this procedure and think, oh,
Speaker 1: this tastes like fat free chocolate. No, So the end
Speaker 1: result here is that we could end up with better
Speaker 1: tasting chocolate with less fat in it in the future,
Speaker 1: which seems pretty awesome to me. Now, earlier I mentioned
Speaker 1: that electroheological fluids are also called smart fluids. That's because
Speaker 1: these fluids can change their viscosity almost instantly in the
Speaker 1: presence of an electric or magnetic field, and then go
Speaker 1: right back to what they were before once the field
Speaker 1: is turned off, and they become really important in ways
Speaker 1: be on making superior chocolate. For example, car manufacturers have
Speaker 1: been using smart fluids and suspension and braking systems. The
Speaker 1: fluid can actually go from relatively thin to thick in
Speaker 1: just a moment's notice, which makes it superior to a
Speaker 1: lot of mechanical solutions that would take time to propagate
Speaker 1: through a system. And you can have a variable suspension
Speaker 1: in this way. Imagine that you have a suspension, it's
Speaker 1: a fluid suspension, like literally, it's a suspension for a
Speaker 1: car with fluid in it, not that it was a
Speaker 1: fluid that has a suspension in it. It's kind of confusing,
Speaker 1: so car suspension's got fluid in it. Very high end
Speaker 1: sports cars have these, and you can set your suspension
Speaker 1: to different modes, like you can predetermine which mode you
Speaker 1: want at any given time. So let's say you're going
Speaker 1: to be driving on like a racetrack, a nice smooth racetrack,
Speaker 1: and you're really going to push the car to its limits.
Speaker 1: You might want a pretty stiff suspension for that to
Speaker 1: really be able to feel the car as you're driving
Speaker 1: along this very smooth surface. But that stiff suspension would
Speaker 1: be a torture device. If you were driving down a
Speaker 1: normal everyday road that had some bumps and maybe some
Speaker 1: potholes in it, that would be very jarring. You would
Speaker 1: feel every single little bump. So in that case, you'd
Speaker 1: want a more loose suspension, a little spring in it.
Speaker 1: So you might want to reduce the viscosity of the
Speaker 1: fluid inside the suspension to allow for more give really,
Speaker 1: and you could do that with a smart fluid and
Speaker 1: just change the electric or magnetic field that ends up
Speaker 1: affecting the viscosity of the fluid. So you can actually
Speaker 1: have settings and say I want a very stiff suspension
Speaker 1: in this circumstance and so it generates the electric field,
Speaker 1: the viscosity increases and you get your stiff suspension, or
Speaker 1: you might say, oh, I want it to be a
Speaker 1: more forgiving suspension, and it turns off that electric field.
Speaker 1: The viscosity decreases and you have your more your suspension
Speaker 1: when more given it. It's a pretty cool idea. I
Speaker 1: chatted with Scott Benjamin about this before I came in here.
Speaker 1: He was very interested when I started talking about chocolate,
Speaker 1: but then when I started talking about smart fluids, he
Speaker 1: really lit up because he knew exactly what I was
Speaker 1: talking about. I mean, Scott is a car genius and
Speaker 1: knows everything there is to know about cars, it seems.
Speaker 1: So we had a good discussion about, you know, the
Speaker 1: physical properties of smart fluids and why they behave the
Speaker 1: way they do. So this technology could be used in
Speaker 1: lots of different applications moving forward. When you can induce
Speaker 1: some mechanical change in a fluid with something as simple
Speaker 1: as an electric or magnetic field, a lot of different
Speaker 1: opportunities open up. But for me, you know, I'm happy
Speaker 1: with the chocolate thing. I'm going to settle for that
Speaker 1: because I do love me some chocolate that wraps up
Speaker 1: the classic tech episode of How Tech Could Make Better Chocolate.
Speaker 1: Hope you enjoyed it. If you have suggestions for topics,
Speaker 1: I should cover future episodes of tech Stuff a couple
Speaker 1: different ways you can let me know. One you can
Speaker 1: go on over to Twitter and you can send me
Speaker 1: a message. The show's handle is tech Stuff hsw or
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Speaker 1: free to download. It's free to use. Navigate on over
Speaker 1: to tech Stuff by putting that into the little search
Speaker 1: field that I'll take it to the tech Stuff podcast page.
Speaker 1: You'll see a little microphone icon. If you click on that,
Speaker 1: you can leave a voice message out, but thirty second
Speaker 1: ten length either way. I hope you're doing well and
Speaker 1: I'll talk to you again really soon. Tech Stuff is
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Speaker 1: favorite shows.