If you didn’t catch the first part of this series on what electronic tests are and how they relate to sustainability, you can find it here! To summarise: there are different types of electronics tests at different parts of the electronics’ life (e.g. initial design vs. end use). They help us improve technology faster. And improved technology is the key to sustainability–from energy-efficient LEDs to environmentally-friendly batteries!
If you’ve read the first article in this series, you might have noticed how a LOT of tests (for everything from hard drives to solar panels to lasers) involves heating them up. It’s one of the most common variables controlled in electronics testing. Why is that? Basically, modern electronics are made with very SPECIFIC chemistry. All the atoms have to be in just the right place (and the places have weird names, like ‘p-n junction’). At higher temperatures, atoms get ‘excited’ and move about more and more. Eventually, they get so ‘excited’ they move away from the places we want them to be. This ‘naughty’, uncontrolled behaviour causes electronics to break. Which is why temperature is an important variable in all tests, and why electronics have cooling fans, heat sinks, etc. in practical applications.
🔑 FACT: for every 10° C increase in temperature, an electronic can break twice as fast.
Other common variables that can affect the lifetime of many types of electronics are the current and voltage they receive. Current is the flow of electrons, resistance slows down the flow, and voltage speeds up the flow.
Alongside these basic variables measured, there are some that are more specific to the electronic being measured. For instance, batteries measure a variable called self-discharge when they age, which is when a battery loses energy without being plugged in. Over time, this decreases the amount of energy the battery has stored. And this measure of aging is becoming more important with electric cars. You wouldn’t want to buy an electric car if you didn’t know how many years it would take before you’d have to buy a new battery. Right?
Behind all these variables is a complicated physics. It has to do with two key terms: failure modes (events that break an electronic); and failure mechanisms (the causes behind those events). Physics variables can measure when a failure mode occurs. For example, a power cable that transmits electricity underwater would undergo corrosion (failure mechanism). Eventually, there would be so much corrosion that the cable would snap (failure mode). And we would detect the cable snapping when current is no longer flowing through the wire (variable).
Though we can use current to monitor failure modes of power cables just like we can use it for laser diodes, there are VERY different failure modes for the two electronics. This is the in-depth explanation of something I mentioned in the first article; it’s REALLY hard to test electronics once they’re deployed in the field. For every electronic you want to test, you have to consider ALL the environmental conditions that could trigger ANY of the unique failure modes for that electronic. And you have to simulate the physics of the situation to understand when the failure mode might be triggered!
I hope you now see why electronics testing is a lot more complicated than it first seems. THIS is the complexity that delays electronics testing and slows down rapid innovation for future sustainable technology. In the next part of the series, I’ll describe the SPECIFIC parts of electronics testing which are slow (in case any of you sustainability innovators have ideas for how to speed up the development of green, new technology)!