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April 19 2012
Ask MAKE: DIY Algae Biofuel
Ask MAKE is a monthly column where we answer your questions. Send your vexing conundrums on any aspect of making to askmake@makezine.com. If we don’t have the answer, we’ll scare up somebody who does.
Phil asks:
I’m curious to learn more about some of the good “DIY algae growing at home” web resources for family scale production of algae fuel. Are there any available kits or books about this yet? (I’d be looking to spend less than $2,500.)
This Stanford student’s YouTube video looks intriguing, although I don’t happen to have a spare centrifuge lying around.
Hi Phil,
As far as I can tell, making liquid fuel from an algae bioreactor does, in fact, require a centrifuge to extract the oils from the algae. However, you can harvest the algae and make solid fuel from it through a simple drying process, which could be used for home heating. But be aware that producing even a small amount of dry fuel requires a sizable amount of biomass. For example, according to Algae Lab “To grow 100g of Spirulina a day would take roughly 20 square meters, or 216 square feet. It would have to get plenty of sun.”
If you’d still like to explore your own algae bioreactor for either solid fuel or food (spirulina), there are a couple of ways to go. Michael Fischer, the Stanford student from the video you sent, shows how to create his setup on an Instructables page. Also, algal fuel guru Aaron Baum sells starter kits through his site Algae Lab. If you want a professional consultant for a larger system, I’d recommend contacting him.
If anyone has experience with algae bioreactors or has more information, please post in the comments.
More:
Browse through all our Ask MAKE columns
April 03 2012
Bones of Blue Plasma
Embodiment is just one of a striking series of skeletal krypton discharge lamps from sculptor Eric Franklin. Franklin’s work makes a nice compliment to Jessica Lloyd-Jones’ neon organs, which we posted about last week. [via adafruit]
Eric Franklin – Luminous Glass sculpture
March 29 2012
How-To: Tell Mammoth Ivory from Elephant Ivory
"Mammoth Ivory tusk hand carved by Japanese master carver." (Wikipedia)
The craft use of any kind of ivory is potentially controversial. We have covered at least one ivory-related project, before, about the use of antique ivory piano keys in scrimshaw, but generally we have steered clear of ivory (I imagine) because it’s such a sensitive and complex subject. Personally, though I often admire the beauty of carved ivory, I have avoided owning or working with it for ethical reasons. On the other hand, if a junk piano with antique ivory keys were to fall into my hands, I would have no problem salvaging and working with them. Indeed, it would seem wasteful not to do so.
There are several alternative / substitute materials available to a person interested in working with ivory. One of these is so-called “fossil” ivory, which is harvested from mammoth remains preserved in Siberian permafrost. Per a 2009 story in The New York Times, “[t]he tusks are more abundant than many people in the West realize. Encased in an upper layer of Siberia’s permafrost are the remains of an estimated 150 million mammoths that lived from 3,600 to 400,000 years ago.”
A 2010 report in the specialist journal Pachyderm describes the annual mammoth tusk harvest: “Every year, from mid-June, when the tundra melts, until mid-September, hundreds if not thousands of mostly local people scour the tundra in northern Siberia looking for mammoth tusks. All are Russians as foreigners cannot obtain a permit to collect tusks in the field. Some tusks are easily seen on the banks of rivers while others are detected on the flat lands.” Further, the report claims, “[i]n recent years, 60 tonnes of mammoth tusks have been exported annually from Russia, mostly to Hong Kong for carving in mainland China.”
Whatever the larger implications of the mammoth ivory trade may be, it has created a practical forensic problem for law enforcement. Buying mammoth ivory is, generally, legal, while buying elephant ivory, generally, is not. But when you’re a customs official staring at a crate full of tusks, how do you know which is which?
Cross sections of elephant (left) and mammoth tusks (right) with outer Schreger lines marked, showing characteristic angle difference.
For an agent “in the field,” the simplest and most useful test is based on natural grain lines in elephant and mammoth tusks called “Schreger lines.” Tusk cross sections can be scanned on the glass of a photocopier, and the angles between Schreger lines near the surface of the tusk measured with ruler, pen, and protractor:
When averages are used to represent the angles in the individual samples, a clear separation between extinct and extant proboscideans is observed. All the elephant samples had averages above 100 degrees, and all the extinct proboscideans had angle averages below 100 degrees.
Further, mammoth ivory sometimes displays characteristic staining in visible and ultraviolet spectra. The U.S. Fish and Wildlife Forensics Laboratory’s Ivory Identification Guide, linked below, has more details, and is a great resource in general for anyone who may be considering working with mammoth ivory.
Ivory Identification Guide – U.S. Fish and Wildlife Service Forensics Laboratory
March 28 2012
“Electric Lungs”
Welsh sculptor Jessica Lloyd-Jones created a series of four gas discharge tubes in the shape of human organs. Besides Electric Lungs, shown above, it includes Optic Nerve, Brain Wave, and Heart. The sculptures were executed at renowned New York glass studio Urban Glass, in collaboration with specialists there. [via adafruit]
Jessica-Lloyd Jones – Anatomical Neon
More:
Incredible electronic bronze brain sculptures
March 27 2012
How Wood Hardness is Measured
In fact, there are now a couple of different procedures, but the traditional method is known as the “Janka hardness test,” named for Austrian wood researcher Gabriel Janka, who invented it in 1906. The test measures the force required to embed a standard-sized steel ball (0.444in/11.28mm diameter) exactly halfway into the surface of a standard-sized sample of the wood. The formal procedure, embodied since 1927 as ASTM standard D143, is not freely available, but J.J. Morlan summarizes the key points well:
Testing is done on wood from the trunk of the tree and is almost always the heartwood. With heartwood there are a handful of exceptions. One that comes to mind is Balsa {Ochroma pyramidale}. Balsa is always milled from sapwood. The standard sample as indicated in ASTM D 143 is to be at 12% moisture content, be clear {no knots}, a solid block of wood having the dimensions of at least 2″ x 2″ x 6″ long and the rate of loading will be machine set at 1/4″ per minute. Two indentations are made on the tangential surface and two indentations on the radial surface. The four indentations are then added together and divided by 4 to get the average value of the force, with the result being declared as the side hardness.When testing is done on a piece of wood with the force applied to the end grain surface, the test is of end hardness. The end hardness of wood/lumber/timber will almost always be higher {harder} than its side hardness.
Morlan also provides a lengthy list of Janka hardness values for various woods, of which the current record holder is Allocasuarina luehmannii, aka “Australian bull-oak,” which require 2.5 tons of pressure. By comparison, Ponderosa pine tests at 480 lbs on the Janka scale, and low-density balsa wood at 88 lbs. The world’s softest wood, by Janka hardness, is Cavanillesia platanifolia, aka “quipo,” at 22 lbs. The Forestry Service research note linked below gives a good historical background and general overview of the Janka test.
Janka Hardness Using Nonstandard Specimens (PDF)
March 02 2012
LittleBits, Backyard Brains, MakerBot at TED
I’m here at TED2012 in Long Beach, CA! I interviewed Ayah Bdeir, the founder and lead engineer of littleBits, an open source library of electronic modules that snap together with tiny magnets for prototyping and play. littleBits won Popular Science’s “Best of Toy Fair 2012″ and Ayah was named a TED Fellow this year.
Gregory Gage of Backyard Brains also showed me how to measure the electrical activity of a neuron in a cockroach leg. At around the 12:00 minute mark, Gregory pumps the electrical signal from music on his iPhone into the cockroach’s leg, causing it to twitch in time with the beat. (The cockroach’s leg will grow back.)
Here’s a short interview with Bre Pettis, co-founder of MakerBot Industries. He shares news about the new Replicator 3D printer, and the printing of an old school mechanical clock with an escapement mechanism. (I called it a “catchment mechanism” in the video — oops.”)
[Cross-posted from BoingBoing]
February 24 2012
Build the Eyeboard Open Source Eye-Tracking Project
When 18-year-old Honduran maker Luis Cruz met a quadriplegic high school classmate and learned about the challenges he and other folks with disabilities face in the light of expensive assistive communication technologies, he was inspired to devise a solution. What Luis came up with is the Eyeboard: an inexpensive yet reliable human-computer interface that detects eye movements using electrooculography (EOG), a biomedical technique based on picking up signals from electrodes placed around the eyes, which in this case enables users who can’t manipulate a mouse or trackpad to move a cursor on a screen. Luis wrote about his project in an eye tracking feature on the pages of MAKE Volume 29, alongside Zach Lieberman’s EyeWriter project. Here is Luis’ article on the Eyeboard design and development:
The eyeball generates a voltage of 0.4mV–1.0mV (millivolts) between its cornea in front and retina in back. If you attach electrodes on opposite sides of the eye, they’ll pick up some of this voltage, depending on where the eyeball is pointing. Looking straight ahead, with the cornea and retina equidistant between the electrodes, there will be no voltage. But with the eyeball angled to one side, you can measure a microvolt-level signal between the
electrodes nearer the cornea and the one opposite. EOG can track both horizontal and vertical movements, but horizontal is easier and more useful. My system, like many others, only tracks horizontal using 3 electrodes: one right next to each eye,and the ground electrode centered on the bridge of the nose or forehead.A processor chip or even an oscilloscope cannot detect such small voltages, so the EOG system must amplify them, while also filtering out any noise from nearby electrical devices and wiring. You can see the circuit I built to accomplish this, along with step-by-step instructions for building my EOG system and programming its microcontroller chip, at makeprojects.com.
To amplify the signal initially, I use an INA118 instrumentation amplifier chip configured with a 100Ω resistor between pins 1 and 8, which gives it a gain of 501. The INA118 chip’s high CMRR (common-mode rejection ratio) of 110dB eliminates common signals that go into both inputs, which removes some noise at the start of the signal path.
Noise from electrode circuits tends to come at high frequencies, so mine uses 2 passive low-pass filters in sequence, to reduce this noise above their cutoff frequency of around 16Hz. With the circuit I used, the formula for the cutoff is 1 /2πRC, where R is resistance and C is capacitance, so with a 100kΩ resistor and a 0.1µF cap, this comes out to 15.9Hz, which is fine; eye movements aren’t so fast that filtering cuts out anything important.
Finally, a capacitor zeroes the signal by removing the DC offset added by the resting potential between the eyes, and a voltage follower circuit lets you connect a higher source impedance device than the EOG output’s impedance, which is useful to connect an oscilloscope or multimeter for troubleshooting. To power the system, I use two 7805 voltage regulators wired in a trick way to supply the circuit with +5V, –5V, and ground (0V), eliminating the need for a dual power supply.
To process the amplified signal when the eyes move horizontally, I feed it into the analog-digital converter pin of an AT-mega328P microcontroller that’s programmed to send the data to a computer via serial port. A Python script on the computer then sends the data to a C++ applet I wrote, which lets the user spell out messages. Looking to the left scrolls down through letters, and looking to the right selects them. To make wearing the electrodes more comfortable, I mounted them to some glasses modded with a headband and super glue. I’ve built several prototypes of these EOG glasses with good results.
I’m still improving this EOG system, including looking for ways to make it more comfortable to wear. I’m pleased to have developed a system for less than $200 that enables disabled people, like my classmate, to communicate, when commercial versions of the same cost a minimum of $10,000. I’d also like to create inexpensive EOG-interface systems for other applications, such as controlling a wheelchair or a television. I just graduated from high school, and what I need most of all in order to pursue these ideas is a scholarship, sponsor, or other funding source so that I can study electrical engineering in the United States.
Here’s the Reuters coverage of Luis’ project from December 2011:
Build your own Eyeboard by following the instructions Luis shared on Make: Projects.
From the pages of MAKE Volume 29:
We have the technology (to quote The Six Million Dollar Man), but commercial tools for exploring, assisting, and augmenting our bodies really can approach a price tag of $6 million. Medical and assistive tech manufacturers must pay not just for R&D, but for expensive clinical trials, regulatory compliance, and liability — and doesn’t help with low pricing that these devices are typically paid for through insurance, rather than purchased directly. But many gadgets that restore people’s abilities or enable new “superpowers” are surprisingly easy to make, and for tiny fractions of the costs of off-the-shelf equivalents. MAKE Volume 29, the “DIY Superhuman” issue, explains how.
February 23 2012
Rock Out Hands Free with Air Guitar Hero
Biomechanical engineer Robert Armiger and surgical roboticist Carol Reiley, both of Johns Hopkins University, created Air Guitar Hero as a fun rehabilitation exercise for people with amputations. The original version they made was a bit costly, but they wrote up a less expensive DIY version, and shared their build instructions with us on the pages of MAKE Volume 29. Now we’ve shared the full how-to on Make: Projects. Whether you intend to build your own or use the concepts to build something entirely different, the info is freely available for you to play with.
How does it work?
When a muscle contracts or flexes, it produces electrical activity. While faint (in the millivolt range), these signals can be detected by placing electrode sensors on the skin. The technology to measure, evaluate, and process muscular electricity is called electromyography (EMG). Air Guitar Hero uses EMG to send signals to the Wii console to control the game. But since the electrical signal generated by twiddling your fingers is very weak, additional computation must be performed to generate reliably accurate commands. The system uses pattern recognition algorithms to identify patterns in the EMG signals and decide which colored button to activate. The algorithms require training data to provide examples of what signal characteristics to look for. First, you must correctly play on-screen notes with the guitar while the electrodes record your EMG signals. Next, the recorded data is used to train a model for recognition the next time you make those movement patterns. Third, practice makes perfect! Playing this type of video game can be useful for building muscle tone and dexterity.
You play air guitar, moving your (A) 4 fingers corresponding to the first 4 “note” buttons on the Guitar Hero controller. (B) Electrodes on your arm detect tiny electrical signals from the muscles that move your fingers. These (C) EMG signals are boosted by (D) amplifiers, each on their own channel. The amplified signals are gathered by the (E) data acquisition board, which sends them on to the (F) laptop computer. The (G) USB video capture device pulls the Guitar Hero video from the (H) Wii video game console into the computer, for purposes of training the software. The (I) Air Guitar Hero software interprets the mixture of EMG signals as one of the 4 button-pressing motions, then sends the corresponding button command over to the (J) hacked GH controller which relays it to the Wii. It sends the Strum command automatically when you hit the note. You’re rocking out!
Here’s a video of Iraq war veteran amputee and Open Prosthetics Project founder Jon Kuniholm demoing the Air Guitar Hero:
From the pages of MAKE Volume 29:
We have the technology (to quote The Six Million Dollar Man), but commercial tools for exploring, assisting, and augmenting our bodies really can approach a price tag of $6 million. Medical and assistive tech manufacturers must pay not just for R&D, but for expensive clinical trials, regulatory compliance, and liability — and doesn’t help with low pricing that these devices are typically paid for through insurance, rather than purchased directly. But many gadgets that restore people’s abilities or enable new “superpowers” are surprisingly easy to make, and for tiny fractions of the costs of off-the-shelf equivalents. MAKE Volume 29, the “DIY Superhuman” issue, explains how.
February 10 2012
Printable Pest Control
Kiwi programmer and farmer John Hart of Lifeboat Farm has been experimenting with using his RepRap to produce mechanical pest control devices so he can leave off the chemical pesticides. Shown above, fused-filament butterfly decoys, spotted with a marker and mounted on stalks of plastic filament in the garden:
The stalks are quite flexible so the butterflies bob about in the wind. They look pretty realistic to me, but more importantly I’ve seen white butterflies hovering around, then leaving without touching down, all this week. Time will tell if any have the courage to sneak in to lay eggs.
The model is available as Thing #6685 by Vik Olliver. John has also developed an interesting printable flytrap, though I haven’t seen the physibles for that one posted anywhere, yet. [Thanks, Tim!]
February 09 2012
3D-Printed Shells for Hermit Crabs
If you can endure the relentless puns, the tag aggregator page for MakerBot’s Project Shellter is a fun read. There are cool pics of the denizens of MakerBot’s official “crabitat” sporting their fused-filament homes (such as “Paris Shelton,” above, in a lovely little daffodil yellow number) as well as oddly touching night-time videos of each crab adopting its new home for the first time. [via nerdstink]
February 04 2012
Bringing Xiphactinus Back to Life
While developing the second phase of their Cretaceous Sea Exhibition, The Hastings Museum in Hastings, NE commissioned a life-size model of a Xiphactinus from Gary Staab, a paleo artist based in Kearney, MO. The Xiphactinus was a large predator fish that lived in the Western Interior Sea during the late Cretaceous Period and skeletal remains of this “X-fish” have been found in many parts of North America, Europe, and Australia. Luckily for us, Gary and his team documented the painstakingly detailed process of creating the life-like model in the excellent video above. [Thanks, Jo!]
January 20 2012
Life Size Junk Mammoth
Junk artist extraordinaire Jud Turner is an old favorite here at MAKE. He’s just moved into a bigger studio and completed his largest piece, ever—a life-size Columbian Mammoth skeleton made from “95% recycled materilas, mostly old farm equipment and agricultural tools.” He’s also posted some cool work-in-progress shots here. [Thanks, Jud!]
January 17 2012
Kim Holleman’s Micro-Environments are Very Much Alive
Combining issues around utopia, environmentalism, and contamination, Kim Holleman will be exhibiting some of her micro-environments at Front Room Gallery in Brooklyn, opening this Friday. Working with vintage scientific beakers and bottles, Kim’s “faux-scientific archive” presents us with miniaturized landscapes that comment on mankind’s chemical footprint, but show that truly defiant biology will grow almost anywhere. “Think ships in a bottle, 2.0,” she says, alluding to the process that the contents of these beakers are not simply put in place, but are grown over time, and therefore create their own stasis and aesthetic.
Front Room Gallery
147 Roebling Street, Brooklyn
Opening: Friday, January 20, 7 – 9 PM
Exhibition: January 20 – February 19, 2012
January 04 2012
LCD Projector Hacked Into a Medical Imaging System
I love stories like this, about how people are making use of off-the-shelf technologies to mimic the effects of more sophisticated and expensive scientific equipment. Yay DIY!
The slow march of optical spectroscopies toward the clinic has been helped along by technologies borrowed from communications electronics. Those technologies are allowing optics researchers to build things that would have been inconceivable or prohibitively expensive a decade ago. For example, Tromberg’s students were able to build a spatial frequency domain imaging system using an off-the-shelf digital light projector. In addition to using it to image their thesis adviser’s bicycling injuries, they have used it to measure the oxygenation of skin flaps during reconstructive breast surgery.
December 23 2011
Grown-Crystal and EL-Wire DNA Lamp
Instructables user LucidMovement built this great lamp out of electro-luminescent wire covered in crystals.
So, of course, all of you reading this have thought to yourself at one time or another “I would absolutely love to grow some crystals on el-wire and then encase it in silicone and acrylic.” No? Oh, well maybe it was just me then. Regardless of whether you have had that thought before or not, I’ll show you how I did it. Compared to many things you could spend weeks doing, it is quite a simple matter. It is, however, dirty, messy, prone to failure–don’t be surprised if you end up growing the crystals on the structure several times over until you settle for one that isn’t what you wanted but “oh hell, it’ll do”.
[Via HaD]
December 21 2011
Music Synthesis Added to Conway’s Game of Life
Dr. John Conway’s cellular automation simulation, the Game of Life has been accentuated with some 8-bit beeps and boops! This project, uploaded by YouTube user golece576, was run on an Altera Cyclone II FPGA. [Via Embedded Ppojects
December 15 2011
Xbox 360 Aquarium
Comparisons have been made to the Macquarium, though personally I don’t think the 360 is yet at the same stage of obsolescence as the original Mac when people started making them into aquariums. It was made from a broken console by Spencer Shepard at Blue World Aquariums, who admits, “my Xbox is still safe and sound by my TV.” The window in the side was cut on a waterjet. [via Hacked Gadgets]
October 24 2011
Colorful Beaded Skulls
Our own Andrew Salomone spotted this beautiful skull, one of eight in a limited edition called Our Exquisite Corpse sold through a trendy London boutique. Seed-beaded art objects like this are commonly identified with the Native American Huichol people of western central Mexico, though the style is dubiously “traditional.” Per Wikipedia:
The beaded art is a relatively new innovation and is constructed using glass, plastic or metal beads pressed onto a wooden form covered in beeswax. Common bead art forms include masks, bowls and figurines. Like all Huichol art, the bead work depicts the prominent patterns and symbols featured in the Huichol religion.
[via CRAFT]
More:
Super Skull Roundupalooza
October 17 2011
Golden Needle Felted Koi
Spotted in the MAKE Flickr pool, from user Christine Prusha, AKA FeltedChicken. The base, simulating water, is made from poured resin, with felted cherry blossoms sprinkled on top.
October 14 2011
BioCurious Officially Opens — Test DNA, Build Equipment, Find a Co-founder and More…
BioCurious is the first hackerspace for biology, open to anyone from any background who’s interested in science. We made our official launch announcement today. See us on Hacker News.
Think science is for geeks in lab coats or little kids growing bean trees in styrofoam cups? Time for a rethink. Science has gone DIY. Thousands of people around the world are part of a new brand of research called DIYbio. This group has thousands of engineers, scientists, entrepreneurs, and students. And lots of artists. This is the kind of collaboration you just don’t get inside institutions.
DIYbiologists are some of the most passionate and creative souls I’ve ever met. I absolutely believe these folks will change the world. Their brains and stick-to-it-ive-ness will help them make discoveries where others might give up for lack of funding, or out of an inability to get published for their work. And because I believe in them, and believe in the power of open, collaborative science, a couple years ago, I put my (proverbial) money where my mouth was.
After some interviews, I found out some members of the Bay Area DIYbio community were excited about science but had paused in their research. Turns out, they were rich in enthusiasm, smarts, and frequently, in capital, but lacked time, access to equipment, and mentors. It seemed like an easy fix: get space; fill it with equipment, professional scientists, amateurs, and beanbags, and make sure the culture stayed open and friendly.
Long story short (get the longer story on our official announcement), the fix was BioCurious. This home for pros, hackers, their families, and friends is now open. We offer co-working, office space, lab space, and dry and cold storage. Check us out on biocurious.org, and for a limited time, get a free day pass.
BioCurious is a non-profit company that is completely volunteer-run. We only exist due to help from the community. A big, virtual hug to our 580+ members, our volunteer staff and especially to the founding team: Kristina Hathaway, Tito Jankowski, Joseph Jackson, Josh Perfetto, and Raymond McCauley. We’ve done something big, and I hope you’ll join us as we change the world of science.
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