Is that a frog? A grasshopper? No! It's a flexible actuator prototype...that can bounce.

Twenty-seven-year-old engineer and YouTuber Carl Bugeja's miniature jumping circuit is basically a coil printed on the flexible PCB (Printed Circuit Board) acting as an electromagnet. The coil behaves as the static side of the actuator. A stack of two permanent magnets is attached to the circuit, resembling arms. The tiny 'living' circuit leaps around the table with ease, much to the awe of Bugeja's audience.

A few weeks ago, he created a ball with 242-RGB-LEDs for playing ping pong. Based on a four-layer flexible PCB, the device was replete with wireless connectivity and smart lighting patterns, with each half comprising 121 LEDs in a circular pattern.

His other projects include a fish robot and a tiny holographic FlexLED. 

If it isn't obvious, the central character in Bugeja's life is a PCB. His first documented project involved a PCB motor, and the next one that distinctively used PCBs was a linear actuator. Then, he chose to venture into new territory - flexible PCBs, starting up FlexAR to market the products to anyone who would like to create their own projects.

The electronics engineer makes the most fascinating robots out of PCBs, documents them, and treats a loyal group of 124,000 (and counting) subscribers to his genius. They cheer for his successes and admire his self-assurance when they lead to failures.

"It's very important to show the failures - in engineering, especially - as they're part of the process," Bugeja tells IE. "When something fails, your mind will start thinking of a hundred reasons why it’s failing, and only one of them will turn out to be the root of the problem. So you would probably be testing other ways why it might be failing, which, if it didn’t fail, you wouldn't be testing. My most valuable lessons in electronics are derived from failures."

Hailing from Malta, one of Bugeja's fondest memories involve building his first robot with his grandfather. "It was an extremely simple robot - it just had a light bulb and a DC motor - but seeing your first robot come to life...that's quite a joyful moment," he says. Bugeja stresses that his grandfather not only passed down his love for electronics but also his passion for woodwork, to his grandson.

Information is available in abundance today but to a budding Maltese electronics enthusiast, books were the main source of information. "Malta is a beautiful island but we didn't have many resources, hackerspaces, or groups. My journey began with breaking toys and figuring out their mechanics. The internet became more accessible as I grew up - that's when I started building small robots by myself. And when I enrolled in university to study electronics engineering, I learned a ton of advanced stuff," says Bugeja.

After his graduation in 2016, he built a startup with his friend, in which the duo worked their way around building small drones. The startup failed, but Bugeja, as with every failure, took home a few lessons. It activated his love for miniatures and simplicity. "I kept thinking of various ways to simplify a drone. That is how the idea of using PCB motors began. PCB design offers various ways in which a product can be simplified. Exploring the same has been the main goal with my projects on YouTube," he says. 

IE sat down with Bugeja to talk about PCBs and more.

This interview has been lightly edited for length and clarity.

Interesting Engineering: Tell us about the behind-the-scenes of a PCB project.

Carl Bugeja: Not every project starts with being feasible. I tackle the project head-on only when I have sufficient data and results. A lot of them take a considerable amount of time. Also, simplification is far from easy, though I constantly try to develop new concepts using the fewest parts possible. Eventually, I hope to make a cheap robot that can be used in swarm robotics. 

IE: Let's dive into flexible PCBs. I find that they've added a very interesting dimension to your projects.

I designed my first flexible PCB around two or three years ago. Flexible PCBs do offer a new dimension to PCB design because mechanically, they give you different possibilities. For example, my LED ball is very hard to do without flexible PCBs. At the same time, you need to watch out when you use them. You'll need to use stiffeners so that the electronic parts in your project do not bend and result in damaging the soldering. In my opinion, it's a new world for PCB design. 

IE: What is the most challenging project you've undertaken with flexible PCBs? 

When I first started, there weren't a lot of makers on YouTube using flexible PCBs. Not many resources were available online either. But I learned a lot from my projects. Some of the most challenging ones have been the robots made from flexible PCBs. With every iteration I made, I found a unique application. Currently, I'm tackling a wheeled robot, one of my upcoming projects on YouTube. It's a better iteration of my previous designs. I find it rather cool as it will comprise just one flexible PCB. Everything will be connected to it, and it will fold up into a robot. Turning a two-dimensional part into a three-dimensional product and ensuring that it is bendable, is an achievement.

IE: How durable are your PCB robots? Do you dismantle them right away after filming a video? 

I think durability is one of my main challenges because, among all the robots that I made, only one is durable. Because most of the robots are weighty, which, after a point, ends up being a hindrance, leading to poor performance. The other challenge would be thermal issues, which are common with other motors too, but there are limits for PCBs.

IE: Do you think open source has unlocked so many avenues for enthusiasts? Several subscriber comments under your videos talk about how well you've explained the matter, and unwittingly helped a group of people very passionate about electronics.

Before I started my channel, I didn't quite believe in open source. But after starting my YouTube journey, I decided that every project of mine will be open source. Because I believe that it's important to show your research, and share it with others. It results in the formation of a community. I will keep sharing my knowledge and making these projects accessible. If anything, I try to make it easier for [my YouTube audience] - I sell electronic kits on my website so that they can access this technology, which can be pricey. 

IE: What is the one thing you wish people knew about you/your work?

Given that I live in Malta, some people don't realize that there are not a lot of resources. For example, we don't have that many electronic shops. I usually buy all my stuff online, which takes ages to get home. Most people don't know that I don't live in a large country where things are more easily accessible. Only four years ago, YouTube opened its creator page for Malta, which was huge. There are not many YouTube creators here. Regarding the project and the shoot on an individual level - both take a long time. There will be soldering issues, bugs in the software...it's not easy. But I try to film as much as I can. Makes the process more fun.

IE: Whose videos do you watch for inspiration on YouTube? 

Before I entered university, I used to watch a lot of EVVblog videos by Dave Jones. I also follow Stuff Made Here. The guy has some really cool videos.