The Mystery Of The Boiled Batteries

While debugging a strange battery failure in a manufacturing process, [Josh] discovered a new (to us) LiPo battery failure mode.

Different battery chemistries react differently to temperature. We’ve used lithium exclusively in high-altitude ballooning, for instance, because of their decent performance when cold. Lithium batteries generally don’t like high temperatures, on the other hand, but besides the risk of bursting into flames, we had no idea that heat could kill them. When the battery’s voltage is already low, though, it turns out it can.

[Josh]’s process required molding plastic with the battery inside, and this meant heating the batteries up. After the fact, he noticed an unreasonably high failure rate in the batteries, and decided to test them out. He put the batteries, each in a different initial charge, into a plastic bag and tortured them all with ice and fire. (OK, boiling water.)

When the batteries got hot, their voltage sagged a little bit, but they recovered afterwards. And while the voltage sagged a little bit more for the batteries with lower initial charge, that’s nothing compared to the complete failure of the battery that entered the hot water with under 1V on it — see they yellow line in the graphs.

battery_voltages

There’s a million ways to kill a battery, and lithium batteries are known not to like being completely discharged, but it looks like the combination of deep discharge and heat is entirely deadly. Now you know.

What Can Happen When You Do Try This At Home

In somewhat of a countdown format, [John McMaster] looked back over the last few years of projects and documented the incidents he’s suffered (and their causes) in the course of doing cool stuff.

[John] starts us off easy — mis-wiring and consequently blowing up a 400V power supply. He concludes “double-check wiring, especially with high power systems”. Other tips and hazards involve situations in which we seldom find ourselves: “always check CCTV” before entering the experiment chamber of a cyclotron to prevent getting irradiated. Sounds like good advice.

hotplate[John] also does a lot of IC decapping, which can involve both heat and nasty acids. His advice includes being ready for large spills with lots of baking soda on hand, and he points out the need to be much more careful with large batches of acid than with the usual smaller ones. Don’t store acid in unfamiliar bottles — all plastics aren’t created equal — and don’t store any of it in your bedroom.

The incidents are listed from least to most horrible, and second place goes to what was probably a dilute Hydrofluoric acid splash. Keyword: necrosis. First place is a DIY Hydrochloric acid fabrication that involves, naturally, combining pure hydrogen and chlorine gas. What could possibly go wrong?

Anyway, if you’re going to do “this” at home, and we know a bunch of you are: be careful, be protected, and be prepared.

Thanks [J. Peterson] for the tip!

Lise Meitner: A Physicist Who Never Lost Her Humanity

It is said that the first casualty of war is the truth, and few wars have demonstrated that more than World War II. One scientist, whose insights would make the atomic age possible, would learn a harsh lesson at the outset of the war about how scientific truth can easily be trumped by politics and bigotry.

Lise Meitner was born into a prosperous Jewish family in Vienna in 1878. Her father, a lawyer and chess master, took the unusual step of encouraging his daughter’s education. In a time when women were not allowed to attend institutions of higher learning, Lise was able to pursue her interest in physics with a private education funded by her father. His continued support, both emotional and financial, would prove important throughout Lise’s early career. Continue reading “Lise Meitner: A Physicist Who Never Lost Her Humanity”

Chewing Gum Plus Carbon Nanotubes

Normally, strain sensors are limited in their flexibility by the underlying substrate. This lead researchers at the University of Manitoba to an off-the-wall solution: mixing carbon nanotubes into a chewing-gum base. You can watch their demo video below the break.

The procedure, documented with good scientific rigor, is to have a graduate student chew a couple sticks of Doublemint for half an hour, and then wash the gum in ethanol and dry it out overnight. Carbon nanotubes are then added, and the gum is repeatedly stretched and folded, like you would with pizza dough, to align the ‘tubes. After that, just hook up electrodes and measure the resistance as you bend it.

The obvious advantage of a gum sensor is that it’s slightly sticky and very stretchy. The team says it works when stretched up to five times its resting length. Try that with your Power Glove.

We’ve seen a couple different DIY flex sensor solutions around these parts, one based on compressing black conductive foam and another using anti-static bags, but the high-tech, low-tech mixture of nanotubes and Wrigley’s is a new one.

Continue reading “Chewing Gum Plus Carbon Nanotubes”

Thomas Midgley, GM, And The Dark Side Of Progress

Scientific improvements that create industries and save millions of lives often come at a price that isn’t revealed until much later. Leaded gasoline helped the automobile industry take off and synthesized Freon extended the lifespan of lifesaving vaccines, but they took an incredible toll on the environment.

Both were invented in the early 20th century by Thomas Midgley, Jr. After graduating from Cornell in 1911 with a degree in mechanical engineering, he worked briefly for National Cash Register where inventor Charles Kettering had just created the first electronic till. In 1916, Midgley started working for Kettering at Dayton Metal Products Company, which soon became the research division of General Motors.

Continue reading “Thomas Midgley, GM, And The Dark Side Of Progress”

The Filmomat Home Film Processing System

The death of film has been widely reported, but technologies are only perfected after they’ve been made obsolete. It may not be instant photography, but there is at least one machine that will take 35mm film and 5×7″ prints and develop them automatically. It’s called the Filmomat, and while it won’t end up in the studios of many photographers, it is an incredible example of automation.

The Filmomat is an incredible confabulation of valves, tubes, and pumps that will automatically process any reasonably sized film, from 35mm to 5×7 color slides. The main body of the machine is an acrylic cube subdivided into different sections containing photo processing chemicals, rinse water, and baths. With a microcontroller, an OLED display, and a rotary encoder, different developing processes can be programmed in, the chemicals heated, developer agitated, and film processed. The Filomat is capable of storing fifty different processes that use three chemicals and a maximum of ten steps.

The video for this device is what sells it, although not quite yet; if enough people are interested, the Filmomat might be sold one day. This is likely the easiest film developing will ever get, but then again a technology is only perfected after it has been made obsolete.

Thanks [WhiteRaven] for sending this one in.

Continue reading “The Filmomat Home Film Processing System”

Basic Toolkit For The Basement Biohacker

Laying hands on the supplies for most hacks we cover is getting easier by the day. A few pecks at the keyboard and half a dozen boards or chips are on an ePacket from China to your doorstep for next to nothing. But if hacking life is what you’re into, you’ll spend a lot of time and money gathering the necessary instrumentation. Unless you roll your own mini genetic engineering lab from scratch, that is.

arduino-based-biolab-data-logger-thumbTaking the form of an Arduino mega-shield that supports a pH meter, a spectrophotometer, and a PID-controlled hot plate, [M. Bindhammer]’s design has a nice cross-section of the instruments needed to start biohacking in your basement. Since the shield piggybacks on an Arduino, all the data can be logged, and decisions can be made based on the data as it is collected. One example is changing the temperature of the hot plate when a certain pH is reached. Not having to babysit your experiments could be a huge boon to the basement biohacker.

Biohacking is poised to be the next big thing in the hacking movement, and [M. Bindhammer]’s design is far from the only player in the space. From incubators to peristaltic pumps to complete labs in a box, the tools to tweak life are starting to reach critical mass. We can’t wait to see where these tools lead.