"The Internet of Things is a vast and growing network of electronic devices - each using only a small amount of power - that collect and share real-time data via the internet. Using low-cost computer chips and wireless networks, many billions of devices are part of this network - from smartwatches to temperature sensors in power stations. This figure is expected to grow to one trillion devices by 2035, requiring a vast number of portable energy sources."

Imagine reading this in 1999. It's amazing to consider what we can achieve with technology today.

The internet of things is just a rehash of ubiquitous computing an idea that was around in 198X already.

It's a bit suspicious that the article doesn't actually mention how much power the system uses. The processor it powers doesn't need very much at all, so it makes one wonder

From what I can find [0] it uses 11 uW per MHz. If I’m not mistaken, that means it could run 100 cores at 1GHz and still only use about 1 watt, which sounds almost as impressive as powering it with algae!

https://www.silabs.com/mcu/32-bit-microcontrollers/arm-corte...

Wow. thanks. Doesn't seem like it would replace all that much lithium then

Size of AA battery and powering the most efficient ARM processor for months with nothing but ambient light? I wonder how this scales.

How many days can a AA battery power that processor for?

Surly it has to outperform a normal solar panels in some way before this has uses? Or am I missing something?

you're not missing anything. they don't outperform normal solar panels. The difference is that this might be easier to set up and maintain in an area with limited technological development.

One of the most extraordinary things today is that solar panels are now so efficient that you can collect light across the whole solar spectrum, then feed that to LEDs that emit in exactly the spectrum that plants want, so you can actually grow more plant yield with less light than they would outside in direct sunlight.

Actually this is missing an extremely important point, which is that the algae generated current even when there was no light (ie overnight). The paper hypothesises this is because it stores some of energy gained for later use.

you mean dark respiration?

not particularly interesting; again, you'd prefer to have a solar panel and a battery, because their efficiencies are far, far higher. You can make a battery out of a potato.

Cant we build a positive feedback loop with algae and solar, like stimulated emission in lasers?

What is stimulated emission in lasers, and how might that concept transfer to algae and solar? I googled the definition, but it was way over my head.

The way lasers work is to have a material (called the "gain material") and put a bunch of energy into it. The energy, in the form of light, bounces around in the material and interacts with it, causing it to line up in very specific ways. Eventually, that light is spit out of the material, typically in a straight line, with all the wavelengths kind of lined up, in phase. An important detail related to the term "stimulated emission" is that when you pump energy into the gain medium, the normal histogram of energy populations (IE, how many molecules are in each energy bucket) is swapped- more counts in the higher energy buckets- and then they release that extra energy in the form of light.

Trying to interpret that comment, I assume they're saying that you could use algae as a gain medium, solar as the light-energy input, and the algae would eventually somehow "lase". i don't see how this could happen as algae would make a terrible gain medium, and concentrating the solar that much would progbably cause them to overheat and die. That said, "solar concentrators" do exist for algae photosynthesis: https://link.springer.com/article/10.1007/s10811-008-9324-6 basically, lenses to provide more light to algae to make it grow faster.

From a solar efficiency standard its definitely not. Algae is something like 2% efficient vs ~20% for PV cells. However, it doesn't need a battery like it would with a solar panel.

Not convinced it will be useful but maybe there are applications out there for it.

I thought the algae themselves might have been performing the computation

They should be able to execute any algaerithm.

The headline made me think I was about to read about something like Beer's pond brain. This is somewhat less out-there cool, but still useful.

I have seen a field studying this and it was insane

with Plankton from Spongebob as the slave driver

Can't wait for my scumputer

Can't wait for water cooling to have algae in the water tanks. :)

It's great to see alternative to traditional electronics that have much lower carbon footprint. Although I don't know how expensive to process is, it seems to not use any rare metals like lithium batteries and solar panels does.

The odds we're about to live in a biopunk world just increased.

Kindof gives new meaning to the term "mining pool"

The linked paper summary says "...we describe a bio-photovoltaic energy harvester system using photosynthetic microorganisms on an aluminium anode..."

How do they prevent the aluminum from oxidizing? Oxidized aluminum is an insulator, which should be a problem for a long lived battery?

I don't have access to the whole paper since it's behind a paywall.

Aluminum forms a passivating oxide layer, but generally this layer is conductive enough that you can still use aluminum as an electrode, except in conditions with extreme pH.

sci-hub comes up empty.

The article is not easily available yet:

"Information: This item is under embargo. To send a request for access to the author or person responsible for this item, please enter the following information. If your request is either approved or declined, you will receive a response to inform you of the outcome. If the request is ignored, you will not receive a response at all, in which case you will not be able to access the item."

https://www.repository.cam.ac.uk/handle/1810/336039

Citation:

Howe, C., Bombelli, P., Savanth, A., Scarampi, A., Rowden, S., Green, D., Erbe, A., et al. Powering a Microprocessor by Photosynthesis. Energy and Environmental Science https://doi.org/10.17863/CAM.83468

True, but following the ORCID link from the main author brings me to:

https://www.science.org/doi/10.1126/sciadv.abm5091

which has the glorious title of 'Synthetic biology and bioelectrochemical tools for electrogenetic system engineering'