If you’ve ever had surgery, you know firsthand how important it is to keep the wound from getting infected. There are special conductive sutures that sense changes in wound status via electrical signal and relay the information to a computer or smart phone. As awesome as those sound, they’re a first-world solution that is far too pricey for places that need it most — developing countries. And surgical wounds in developing countries are about four times more likely to get infected than those in the US.
Beets, and other fruits and vegetables like blackberries, plums, and blueberries are natural indicators of pH. They have a compound called anthocyanin that gives them both their pigment and this cool property. Beets are perfect because they change color at a pH of nine — the same pH level of infected human skin, which is normally around five.
[Dasia] experimented with several types of suture thread to see which ones would absorb the beet juice in the first place. She settled on a cotton-polyester blend that is braided. While it probably helps absorb the beet juice, it would also give bacteria several places to hide. Another problem is that many surgeries involve cutting muscle, too, and by the time a deeper infection would show up on the sutures, it would be pretty late in the game. But if these color-changing sutures can be made to be cost-effective, safe for skin, and of course, keep wounds together, this solution is way better than nothing at all and definitely worth producing. You can see [Dasia] talk about her project in the video below.
Want to know more about natural pH indicators? Sure you do.
Automation is a lofty goal in many industries, but not always straightforward to execute. Welding car bodies in the controlled environment of a production line is relatively straightforward. Maintaining plants in a greenhouse, however, brings certain complexities due to the unpredictable organic processes at play. Hexagrow is a robot that aims to study automation in this area, developed as the final year project of [Mithira Udugama] and team.
The robot’s chassis is a very modern build, consisting of carbon fiber panels and 3D printed components. This kind of strength is perhaps overkill for the application, but it makes for a very light and rigid robot when the materials are used correctly.
It’s the sensor package where this build really shines, however. There’s the usual accoutrement of temperature and humidity sensors, and a soil moisture probe, as we’d expect. But there’s more, including an impressive soil pH tester. This involves a robotic arm with a scoop to collect soil samples, which are then weighed by a load cell. This is then used to determine the correct amount of water to add to the sample. The mixture is then agitated, before being tested by the probe to determine the pH level. It recalls memories of the science packages on Mars rovers, and it’s great to see this level of sophistication in a university project build. There’s even a LIDAR mounted on top for navigation purposes, though it’s not clear as to whether this sensor is actually functionally used at this point in development.
Anyone who owns their own pool knows it’s not as simple as filling it up with water and jumping in whenever you want. There’s pool covers to deal with, regular cleaning with the pool vacuum and skimmers, and of course, all of the chemicals that have to be added to keep the water safe. While there are automatic vacuums, there aren’t a whole lot of options for automating the pool chemicals. [Clément] decided to tackle this problem, eliminating one more task from the maintenance of his home. (Google Translate from French.)
The problem isn’t as simple as adding a set amount of chemicals at a predetermined time. The amount of chemicals that a pool owner has to add are dependent on the properties of the water, and the amount of time that’s elapsed since the previous chemical treatment, and the number of people who have been using the water, and whether or not the pool cover is in use. To manage all of this, [Clément] used an ORP/Redox probe and a pH probe, and installed both in the filtration system. The two probes are wired to an Arduino with an ethernet shield. The Arduino controls electrically actuated chemical delivery systems that apply the required amount of chemicals to the pool, keeping it at a nice, healthy balance. Continue reading “Home Pool Added To Home Automation”→
Scientific research, especially in the area of robotics, often leverages cutting-edge technology. Labs filled with the latest measurement and fabrication gear are unleashed on the really tough problems, like how to simulate the exquisite sensing abilities of human skin. One lab doing work in this area has taken a different approach, though, by building multi-functional sensors arrays from paper.
A group from the King Abdullah University of Science and Technology in Saudi Arabia, led by [Muhammad M. Hussain], has published a fascinating paper that’s a tour de force of getting a lot done with nothing. Common household items, like Post-It notes, kitchen sponges, tissue paper, and tin foil, are used to form the basis of what they call “paper skin”. Fabrication techniques – scissors and tape – are ridiculously simple and accessible to anyone who made it through kindergarten.
They do turn to a Circuit Scribe pen for some of their sensors, but even this nod to high technology is well within their stated goal of making it possible for anyone to fabricate sensors at home. The paper goes into great detail about how the sensors are made, how they interact, and how they are interfaced. It’s worth a read to see what you can accomplish with scraps.
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.
Taking 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.
We’ve mentioned that it’s hard to find someone not selling or crowd funding something at Maker Faire. Despite the fact that [Ryan Edwards] is selling his boards, we still got the feeling that he’s a hacker who is selling just to make sure the idea he had is available for other hackers to use. He showed us his interface boards for inexpensive pH probes.
Since we’re always looking for more chemistry hacks to run, it was nice to hear [Ryan’s] description on how these probes (which can be had for around $9 on eBay) actually work. It turns out it’s all about salt. When it comes to the electronics, the board provides a connector for the probe on one edge, and pins for voltage, ground, and I2C on another. Rig this up with your microcontroller of choice and you’ll be building your own automatic pool doser, fish tank minder, or one of a multitude of food-related hacks.
Controlling the pH level of a solution is usually a tedious task. Adding an acid or base to the solution will change the pH, but manually monitoring the levels and adding the correct amount isn’t fun. [Reza] rigged up an automated pH controller to keep a solution’s pH steady.
The build uses an Arduino with a LCD shield, screw terminal shields, and [Reza]’s own pH shield attached. A peristaltic pump is used to pump the pH down acid into the solution. This type of pump isolates the fluid from the pump parts, preventing contamination of the solution. The pump is controlled using a PowerSwitch Tail, allowing the Arduino to control the flow of fluid.
An Omega pH probe is used to read the pH level. [Reza]’s open source firmware has support for calibrating the probe to ensure accurate readings. Once it’s set up, the screen displays the pH level and the current state of the system. The pump is enabled when the pH rises out of the desired range.
After the break, check out a video walk through of the device.