TENGs in Space

Most of the time, I keep these blog posts reasonably focused on writing, or conceivably related to writing, or at least storytelling.  This is a writing site, after all, and you don’t come here to read my random musing on geopolitics or current events.  Even with the exceptions I give myself for “educational content,” I try to choose topics that can at least be vaguely connected to writing or reading (even if it might just be making your science fiction a little more realistic).  This time, as you probably already surmised, I am making an exception.  Years ago, I shared an article about triboelectric nanogenerators (TENGs), and I suggested I might follow up with more detail someday.  Since then, I launched one on a rocket.

Triboelectric nanogenerators take advantage of material properties to convert small scale mechanical energy, like the vibration of someone walking, into electrical energy.  Since the article I shared before, these devices have been explored thoroughly in terrestrial settings, with experiments testing different combinations of materials under diverse configurations and conditions.  These devices function because one of the materials will strip electrons from the other material when they come into contact with sufficient kinetic energy (a low threshold is ideal for most TENGs), creating a potential difference (a voltage), which can be used to power an electrical circuit.  These outputs voltages are usually in the millivolt range, but that can still be plenty for small-scale applications like low SWaP sensors.  Alternatively, a system of capacitors can be wired into the circuit so that the energy is collected over time and released later to power a larger, more power-hungry device intermittently.

The technology fascinates me because of its potential broad applicability and its efficiency.  I find the idea of converting what is effectively waste energy, like errant vibrations in a system, into electrical energy that we can use to some deliberate purpose compelling (TENGs can also be used as sensors, measuring the amount and/or direction of vibrations by measuring a previously characterized voltage reaction).  Since spacecraft are SWaP constrained, it occurred to me that TENGs could find great utility in astronautical applications, taking advantage of otherwise “wasted” energy to increase a spacecraft’s power budget, or providing operators insight through telemetry based on TENG performance.  However, I found almost no exploration in the literature of TENG applications for spaceflight.

Separately, I volunteer as a STEM mentor for some middle school students.  Earlier this year, they were participating in a program called Cubes in Space, which gave them the opportunity to design an experiment to fly on a high-altitude balloon or a sounding rocket.  Both these platforms are often used to increase the technology readiness level of technologies for spaceflight applications before they are flown on an actual spacecraft, so I suggested that they might test a TENG on one of these platforms.  Based on the factors assessed, the sounding rocket made the most sense.  I helped the students design a TENG that would utilize common materials, 3D print it, assemble it, and perform pre-testing on the device before packaging it for launch on a sounding rocket.

This brings us back to that line I tossed out in the first paragraph.  The TENG launched successfully on a sounding rocket back in June (you can watch the launch here), and the students will now test its performance post spaceflight and compare it to performance pre spaceflight.  With this information in hand, we can refine the design, perhaps even pursue publishing a paper or filing for a patent, and add to the nascent literature on TENG application in astronautics.

This time, I have no connection for you, however contrived, to explain how this relates to writing or storytelling.  This is firmly in the realm of my “real” work.  It’s not the first time something I helped designed flew on a rocket, but it is the first time that something I helped design flew on a rocket without being part of some larger program, so I wanted to share.  Plus, part of the Cubes in Space program involves generating publicity for the program, so I suppose this serves that end.  If there’s a point, it’s that space can be more approachable than you might think, and that innovation and invention need not be, and usually aren’t, the result of waiting for a eureka moment.  Rather, they come from small steps forward like this one, and anyone can do it.  Even a hobbyist author and a team of middle school students.