The “P Cell” Is Exactly What You Might Suspect

August 6, 2018 by Donald Papp 34 Comments

[Josh Starnes] had a dream. A dream of a device that could easily and naturally be activated to generate power in an emergency, or just for the heck of it. That device takes in urea, which is present in urine, and uses it to generate a useful electrical charge. [Josh] has, of course, named this device the P Cell.

An early proof of concept uses urine to create a basic galvanic cell with zinc and copper electrodes, but [Josh] has other ideas for creating a useful amount of electricity with such a readily-available substance. For example, the urea could be used to feed bacteria or micro algae in a more elegantly organized system. Right now the P Cell isn’t much more than a basic design, but the possibilities are more than just high-minded concepts. After all, [Josh] has already prototyped a Hybrid Microbial Fuel Cell which uses a harmonious arrangement of bacteria and phytoplankton to generate power.

[Josh]’s entries were certainly among some of the more intriguing ones we saw in the Power Harvesting Challenge portion of The Hackaday Prize, and we’re delighted that his ideas will be in the running for the Grand Prize of $50,000.

Thermal Actuators: Hydraulic Motors That Feed On Temperature Changes

August 2, 2018 by Donald Papp 4 Comments

These Fluid Displacement Thermal Actuators designed by [Andrew Benson] are a delightful and profoundly different approach to the Power Harvesting Challenge portion of The Hackaday Prize. While most projects were focused on electrical power, [Andrew]’s design is essentially a mechanical motor that harnesses the fact that Phase Change Materials (PCMs) change volume when they go from liquid to solid or vice-versa; that property is used to provide a useful hydraulic force. In short, it’s a linear actuator that retracts and expands as the PCM freezes or melts. By choosing a material with melting and freezing temperatures that are convenient for the operating environment, an actuator can be reliably operated virtually for free. A proof of concept is the device shown here; a model of a sun-shade that deploys when a certain temperature is reached and retracts when it has cooled.

Sunshade concept, from deployed (top) to retracted (bottom).

Turning temperature changes into useful physical work is the principle behind things like wax motors and even some self-winding clocks, but what [Andrew] has done is devise a useful method of interfacing directly to the fluids; abstracting away the materials themselves in order to provide mechanical power on the other end. These devices, in general, may not be particularly efficient but they have very few moving parts, are astonishingly reliable, and can operate at virtually any scale. [Andrew] has been thinking big, many of his application ideas are architectural in nature.

[Andrew] was inspired to enter his design for The Hackaday Prize, and we’re glad he did because it was selected as one of the finalists in the Power Harvesting Challenge, and will be in the running for the $50,000 Grand Prize. If you also have an idea waiting for an opportunity to shine, now is the time. The Human-Computer Interface Challenge is up next, followed by the Musical Instrument Challenge. All you really need to enter is a documented concept, so sharpen your pencils and give your idea a shot at reaching the next level.

PTPM Energy Scavenger Aims For Maintenance-Free Sensor Nodes

August 1, 2018 by Donald Papp 13 Comments

[Mile]’s PTPM Energy Scavenger takes the scavenging idea seriously and is designed to gather not only solar power but also energy from temperature differentials, vibrations, and magnetic induction. The idea is to make wireless sensor nodes that can be self-powered and require minimal maintenance. There’s more to the idea than simply doing away with batteries; if the devices are rugged and don’t need maintenance, they can be installed in locations that would otherwise be impractical or awkward. [Mile] says that goal is to reduce the most costly part of any supply chain: human labor.

The prototype is working well with solar energy and supercapacitors for energy storage, but [Mile] sees potential in harvesting other sources, such as piezoelectric energy by mounting the units to active machinery. With a selectable output voltage, optional battery for longer-term storage, and a reference design complete with enclosure, the PPTM Energy Scavenger aims to provide a robust power solution for wireless sensor platforms.

High Efficiency, Open-Sourced MPPT Solar Charger

July 31, 2018 by Donald Papp 28 Comments

A few years ago, [Lukas Fässler] needed a solar charge controller and made his own, which he has been improving ever since. The design is now mature, and the High Efficiency MPPT Solar Charger is full of features like data logging, boasts a 97% efficiency over a range of 1 to 75 Watts, and can be used as a standalone unit or incorporated as a module into other systems. One thing that became clear to [Lukas] during the process was that a highly efficient, feature-rich, open-sourced hardware solution for charge controllers just didn’t exist, at least not with the features he had in mind.

Data logging and high efficiency are important for a charge controller, because batteries vary in their characteristics as they recharge and the power generated from things like solar panels varies under different conditions and loads. An MPPT (Maximum Point Power Tracking) charger is a smart unit optimized to handle all these changing conditions for maximum efficiency. We went into some detail on MPPT in the past, and after three years in development creating a modular and configurable design, [Lukas] hopes no one will have to re-invent the wheel when it comes to charge controllers.

Vampire Charger Is A Rugged Anything-to-5VDC Converter

July 29, 2018 by Donald Papp 43 Comments

USB sockets providing 5 VDC are so ubiquitous as a power source that just about any piece of modern portable technology can use them to run or charge. USB power is so common, in fact, that it’s easy to take for granted. But in an emergency or in the wake of a disaster, a working cell phone or GPS can be a life saver and it would be wise not to count on the availability of a clean, reliable USB power supply.

That’s where the Vampire Charger by [Matteo Borri] and [Lisa Rein] comes in. It is a piece of hardware focused on turning just about any source or power one might possibly have access to into a reliable source of 5 VDC for anything that can plug in by USB. This is much more than a DC-DC converter with a wide input range; when they say it is made to accept just about anything as an input, they mean it. Found a working power source but don’t know what voltage it is? Don’t know which wire is positive and which is negative? Don’t even know whether it’s AC or DC? Just hook up the alligator clips and let the Vampire Charger figure it out; when the light is green, the power’s clean.

The Vampire Charger was recently selected to move on to the final round of The Hackaday Prize, netting $1000 cash in the process. The next challenge (which will have another twenty finalists receiving $1000 each) is the Human-Computer Interface challenge. All you need to enter is an idea and some documentation, so dust off that project that’s been waiting for an opportunity, because here it is.

Micro-Organisms Give Up The Volts In This Biological Battery

July 27, 2018 by Donald Papp 18 Comments

Battery cells work by chemical reactions, and the fascinating Hybrid Microbial Fuel Cell design by [Josh Starnes] is no different. True, batteries don’t normally contain life, but the process coughs up useful electrons all the same; 1.7 V per cell in [Josh]’s design, to be precise. His proof of concept consists of eight cells in parallel, enough to give his cell phone a charge via a DC-DC boost converter. He says it’s not known how long this can be expected to last before the voltage drops to an unusable level, but it works!

Eight-cell, 3D printed proof of concept.

There are two complementary sides to each cell in [Josh]’s design. On the cathode side are phytoplankton; green micro algae that absorb carbon dioxide and sunlight. On the anode side are bacteria that break organic material (like food waste) into nitrates, and expel carbon dioxide. Version 2 of the design will incorporate a semi-permeable membrane between the cells that would allow oxygen and carbon dioxide to be exchanged while keeping the populations of micro-organisms separate; this would make the biological processes more complementary.

A battery consisting of 24 cells and a plumbing system to cycle and care for the algae and bacteria is the ultimate goal, and we hope [Josh] can get closer to that now that his project won a $1000 cash prize as one of the twenty finalists in the Power Harvesting Challenge portion of the Hackaday Prize. (Next up is the Human Computer Interface Challenge, just so you know.)

Bringing Augmented Reality To The Workbench

July 26, 2018 by Donald Papp 12 Comments

[Ted Yapo] has big ideas for using Augmented Reality as a tool to enhance an electronics workbench. His concept uses a camera and projector system working together to detect objects on a workbench, and project information onto and around them. [Ted] envisions virtual displays from DMMs, oscilloscopes, logic analyzers, and other instruments projected onto a convenient place on the actual work area, removing the need to glance back and forth between tools and the instrument display. That’s only the beginning, however. A good camera and projector system could read barcodes on component bags to track inventory, guide manual PCB assembly by projecting which components go where, display reference data, and more.

An open-sourced, accessible machine vision system working in tandem with a projector would open a lot of doors. Fortunately [Ted] has prior experience in this area, having previously written the computer vision code for room-scale dynamic projection environments. That’s solid experience that he can apply to designing a workbench-scale system as his entry for The Hackaday Prize.