Introduction

Welcome to the MEMSYS Tech Blog series! We’re here to share our journey in Energy Harvesting technology, highlight the awesome work we’re doing, and invite you to be part of it. Whether you’re a tech enthusiast or just curious, we hope to spark your interest, get you involved, and show why innovation at MEMSYS is driving the future—one breakthrough at a time.

In this first post, we’ll focus on vibrations, why they matter, and last but not least: how can we harness them?

Table of Contents:

• Vibration basics
• Linear systems and resonance
• Nonlinear and compliant systems
• Traditional Vibration Energy Harvesting
• MEMSYS Vibration Energy Harvesting
• Conclusions

About the author

Thijs Blad is founder and CEO/CTO of MEMSYS. He is a Mechanical Engineer and holds a PhD on the topic of Motion Energy Harvesting. Today he runs the team of MEMSYS engineers that continue to push the boundaries of sustainable, reliable energy for wireless devices.

Vibration basics

Vibrations are repeated oscillations—back-and-forth movements—that occur in everything from guitar strings and engines to buildings and electronics. In physics, we often model these motions using sine waves, which describe how displacement changes over time in a smooth, periodic way.

Key properties of a vibration include amplitude (how far the system moves from its resting position), frequency (how many cycles happen per second, measured in Hertz), and phase (which tells us where in the cycle the motion begins). These characteristics help us analyze and predict how systems respond to different forces.

While vibrations can cause issues like noise, fatigue, or structural damage, they also offer valuable opportunities—especially in the field of energy harvesting. Vibration energy harvesters are devices that convert mechanical energy from vibrations into electrical energy. They’re typically designed to resonate with ambient vibrations, allowing them to efficiently generate a lot of power. This is especially useful for powering small electronics like wireless sensors in hard-to-reach or battery-restricted environments.

In short, understanding vibrations isn’t just about preventing problems—it’s also about tapping into a renewable source of energy hiding in plain sight.

“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.”

–Nikola Tesla.

The graph below illustrates the key properties of a vibration by showing a plot of a sine wave with a frequency of 2 Hz, an amplitude of 1.5 and no phase offset. What you see is that this vibration completes two oscillations per second; this corresponds to a period of 0.5 seconds.

Linear systems and resonance

A linear system is one where the output is directly proportional to the input. That means if you double the input (e.g. frequency, or amplitude), the output doubles too. These systems also follow the principle of superposition, which means the response to multiple inputs is just the sum of the individual responses. In other words, linear systems are predictable—they behave in a straight, consistent way.

Many physical systems can be modeled as linear, especially when working with small motions or forces. Springs, electrical circuits, and most vibrating structures can often be approximated as linear systems, which makes them much easier to analyze using equations.

Proportionality                                  Superposition

One important phenomenon in linear systems is resonance. This happens when a system is forced at its natural frequency—the frequency at which it naturally likes to oscillate. At resonance, a small periodic input can build up over time, leading to very large oscillations. It’s like pushing a swing at just the right rhythm—each push adds more energy, and the swing goes higher. In many mechanical systems or structures, resonance can be dangerous as it may lead to uncontrollably large motions that can lead to damage or even failure (this is the textbook example of the Tacoma Narrows Bridge). For vibration energy harvesters, leveraging resonance can be a particularly useful strategy to convert a small vibration input to a large motion, and therefore a high power output.

Compliant mechanisms and nonlinear systems

Compliant mechanisms are mechanical systems that achieve motion through deformation of elastic parts rather than rigid bodies connected by joints. Instead of hinges, bolts, or gears, they consist of parts that bend and flex—kind of like how a paperclip can act like a spring. Compared to rigid-link mechanisms, these systems are often simpler and can be manufactured from a single part, and they do not suffer from friction, backlash, and wear. This means that they can be produced in a low-cost way and have very predictable behaviour. Engineers use them in everything from micro-scale devices (like sensors in wearables or medical tools) to soft robotics, where flexibility is a big advantage.

Compliant mechanisms that undergo large deformations are often nonlinear. A nonlinear system is one where the relationship between input and output is not proportional. That means doubling the input doesn’t just double the output—it might triple it, reduce it, or cause a completely different behavior altogether. These systems don’t follow the rules of superposition, so their behavior is often more complex, unpredictable, and harder to model with simple equations. Nonlinear systems show up everywhere in the real world, especially when dealing with large motions or materials that stretch or deform in unusual ways. Together, nonlinear and compliant mechanisms show that sometimes, bending the rules—literally—can lead to smarter, more efficient, and more innovative designs.

Traditional Vibration Energy Harvesting

Vibration energy harvesting is the process of capturing mechanical energy from vibrations and converting it into electrical energy. It’s a way to take motion that would otherwise go to waste—like the shaking of a machine, the hum of an engine, or even footsteps—and turn it into useful power. Vibration energy harvesting is particularly useful for powering small, low-energy devices like wireless sensors, especially in places where it’s hard to replace batteries—like inside machinery, on bridges, or in remote environments. It’s a smart, sustainable way to make use of energy that’s already there, just waiting to be captured.

The basic idea is pretty straightforward: when something vibrates, it has kinetic energy. If you connect that vibrating object to a system that can convert motion into electricity, you can harvest that energy. Systems that facilitate this conversion are called transducers and common methods include piezoelectric materials (which generate electricity when they’re squeezed or bent), electromagnetic systems (which change a magnetic field in a coil of wire), and electrostatic systems (which change the capacitance of a capacitor and collect energy from the redistribution of the charges).

Many energy harvesters are designed to work at resonance—when the frequency of the surrounding vibration matches the system’s natural frequency. This is a very effective method to extract a lot of power from regular motions. A machine running at a fixed speed is a great example of a situation where resonance could be used. In such cases, the amplitude of the response (meaning the motion of the mass of energy harvester within the housing) can be much larger than the amplitude of the excitation (the motion of the machine, in this case). The amplification that can be achieved in this way is denoted by the quality factor of the system, which is governed by the damping of the system. The lower the damping, the higher the quality factor, and the more amplification that can be achieved in this way. The result of this is that a lot of power can be generated.

MEMSYS Vibration Energy Harvesting

MEMSYS is exploring an alternative approach to vibration energy harvesting. instead of using linear systems and resonance, we use a nonlinear systems based on compliant mechanisms. Through this method, our systems do not suffer from the drawbacks of resonance and may capture energy from a wide range of frequencies. What this means is that our systems can respond effectively to different types of motion—fast or slow, strong or weak. This is especially useful in real-world environments where vibrations aren’t always consistent or predictable.

What is remarkable about our technology is that we found a way to retain the ability to harvest energy from low acceleration levels without relying on resonance. This makes MEMSYS ideal for powering small, low-energy devices in environments where only gentle motion is available. In short, MEMSYS turns unpredictable, low-level vibrations into reliable, usable power—without needing perfect conditions to do it.

Conclusions

MEMSYS’s innovative energy harvesting technology uses nonlinear dynamics and compliant mechanisms to capture vibrations across a broad frequency range, even at low acceleration levels. Unlike traditional systems that rely on resonance, our approach is more adaptable and efficient in real-world environments.

Stay tuned for our next post!