How Structural Electronics Enables 3D, Flexible, and Wearable Integration

I spent a week redesigning circuits because a mechanical engineer couldn't change an enclosure. The analog signals had to wrap around the entire board, doubling trace length, all because cables needed to exit specific sides of the box.

That was traditional electronics. Structure first, circuits second.

Structural electronics flips everything. The circuit becomes the structure. The structure becomes the circuit.

Structural Electronics: What Becomes Possible

Imagine a smartwatch where the band itself monitors your pulse, not through attached sensors, but through conductive fibers woven directly into the material to detect blood flow patterns.

The display bezel contains touch sensors, and the crown integrates pressure detection. Every surface becomes functional while maintaining the mechanical properties you expect.

This is already happening. Recent breakthroughs in liquid metal circuits enable exceptional conductivity with high stretchability, creating electronics that bend, twist, and stretch like fabric.

Structural Electronics: Beyond Wearables

Smart clothing represents just the entry point. Research in digital embroidery has created garments that monitor health during daily activities while maintaining durability and breathability.

But the real transformation happens in applications where traditional electronics fail.

Imagine aircraft wings embedded with stress sensors throughout the structure - not mounted on the structure, but part of it. Every rivet, every panel becomes a data collection point without adding weight or complexity.

In the automotive industry, dashboards evolve into single, integrated units. The plastic housing contains all the circuits for displays, controls, and sensors. No separate PCBs. No wire harnesses. No assembly of discrete components.

The Manufacturing Revolution

Traditional electronics require multiple steps:

1. Design the PCB.
2. Manufacture the board.
3. Assemble components.
4. Design the enclosure.
5. Integrate everything.

Structural electronics collapse this into a single manufacturing process. MIT's 3D-printed electronics can be manufactured anywhere, breaking traditional supply chain models entirely.

The implications for mechanical engineers are profound. You're no longer designing containers for electronics. You're designing functional materials. Weight disappears as a constraint. When circuits integrate into existing structures, electronic functionality adds virtually no mass to the system.

But mixing these two worlds isn't always easy. Even though there are clear benefits, joining these separate areas brings new problems and opportunities for both mechanical and electrical engineers.

What Mechanical Engineers Must Now Consider

Here's what most mechanical engineers don't realize about electrical constraints. When you force longer signal paths due to mechanical decisions, you're not just adding copper traces. You're adding resistance, inductance, and capacitance to the signal path. Every millimeter matters electrically.

Signal integrity becomes your problem, too. Electrical signals don't flow like water through pipes. At modern frequencies, traces become transmission lines with characteristic impedance. The impedance depends on trace width, thickness, and distance to ground planes. Change the mechanical stackup, change the electrical performance directly.

High-speed digital signals are especially sensitive. A 1-gigahertz clock signal has wavelengths measured in centimeters. Your mechanical decisions directly impact signal timing.

EMI and Power Distribution Challenges

Digital switching creates electromagnetic noise. Every signal transition generates current spikes that cause voltage fluctuations in the ground system.

Traditional PCBs use dedicated power and ground planes to maintain clean and stable power distribution. However, structural electronics must embed power distribution directly within the mechanical structure itself. In these systems, power traces are formed in flexible materials, and their resistance changes as the structure bends.

As a result, components located in different parts of the structure may experience varying supply voltages when the material deforms. Electromagnetic compatibility becomes a system-level architectural concern. The mechanical structure must simultaneously provide electromagnetic shielding while preserving flexibility and mechanical functionality.

Loop areas play a critical role, determining both electromagnetic emissions and susceptibility to interference. In flexible structures, these loop areas change dynamically as the system moves, leading to continuously shifting electromagnetic behavior.

Smart Infrastructure Takes Shape

Building materials embedded with sensors create structures that monitor their own health. Concrete beams can detect stress and fatigue, while bridge cables report tension and vibration. The construction industry transforms when structural elements become intelligent, enabling real-time insight into performance and integrity.

Maintenance shifts from scheduled intervals to predictive analytics based on continuous data streams. Instead of replacing components by the calendar, engineers can act precisely when needed, improving safety, longevity, and cost efficiency.

Medical devices benefit enormously from similar principles. Prosthetics integrate sensors and actuators to enhance responsiveness. Surgical implants can monitor healing progress and detect complications early. Even bandages are evolving, tracking wound recovery and automatically adjusting medication delivery.

Each application demands new thinking about form and function. The mechanical properties of materials must not only serve their intended structural or medical purposes but also support embedded electronic functionality, blending durability, flexibility, and intelligence into a single cohesive design.

Aerospace Shows The Future

High-reliability applications demonstrate structural electronics' potential most clearly. One such application is air travel and space. These applications require reliability standards that push electronics toward maturity faster than consumer applications alone would achieve. 

With new electric aircraft quickly being developed thanks to new and rapid increases in the energy density of batteries, we are able to help further eliminate weight while maintaining safety through the structural and thermal optimization of electrical enclosures, says ASR Engineering in their article Aerospace Electronics: What Role Does it Play? - ITChronicles. 

Tests in these environments have already cut down stress on parts by over 80% and made them last much, much longer. That’s been achieved through the mechanical optimization design combined with electronics alone. With structural electronics on the rise, we are ready to take these improvements even further.

While weight savings remain a key motivation, the real innovation lies in the new capabilities structural electronics enable. Because these systems are built directly into structural components, they offer exceptional strength and functionality, ideal for monitoring an aircraft’s health, detecting and analyzing lightning strikes, and measuring flight performance in real time. Although many of these tasks are still performed using traditional systems, integrated electronics promise a smarter, more efficient future.

Such applications demand extreme reliability, ensuring that structural electronics will advance more rapidly than if they were limited to everyday consumer products.

Finally, military and space applications command premium pricing, and this higher level of investment helps fund the research and development that eventually brings these technologies to the consumer market.

Material Properties You Need to Understand

With structural electronics being integrated into new products, component selection changes completely. Traditional electronic components assume rigid mounting on flat surfaces. But structural electronics require components that handle mechanical stress while maintaining electrical performance. This added complexity forces electrical engineers to expand their awareness and parametric searches for parts on electronics suppliers websites.

That means things like package types matter more than ever. For instance, ball grid array packages that work well on rigid PCBs may have solder joint cracks under flexural stress. Introducing challenges that traditional printed circuit board designs and electronics engineers didn’t have to consider until now. Even benign factors like component orientation affects reliability based on stress distribution patterns, not simply optimizing for assembly costs and routing.

Passive components change behavior under mechanical stress. Ceramic capacitors may exhibit piezoelectric effects, changing capacitance when mechanically stressed. So capacitance ranges must be taken into account beyond the standard scope from the manufacturer. 

In fact, I can see a reality where manufacturers are updating or creating new capacitor types that have tolerances specifically for stress and strain and shown on special mechanical stress curves in their data sheets.

Another factor is how temperature effects on devices will multiply in complexity. Electronic components have temperature coefficients that affect behavior greatly, especially their resistance levels. In structural electronics, thermal expansion is no longer a mechanical and spacing problem, but becomes an electrical problem as conductor spacing changes.

Structural Electronics: The Tool Evolution

So how do we address these new challenges? Traditional design tools have long assumed a clear separation between the mechanical and electrical domains. While that distinction still mostly holds, structural electronics are increasingly blurring the boundaries between the two, often more than existing tools and processes can comfortably handle.

Traditionally, Mechanical Computer-Aided Design (MCAD) software is focused on mechanical design, while Electrical CAD (ECAD) and EDA (Electronic Design Automation) software is focused on electrical design. In some companies, especially in earlier times, simulation and design environments used to be totally separated. Nowadays, it is more common for simulation engineers to work on multidisciplinary models that combine mechanical, electrical, and control systems. This is prevalent in automotive and aerospace industries, as mentioned earlier. Physics-based simulation at this level is called virtual commissioning, where mechanical, electrical, and control functions are tested simultaneously within a unified simulation environment. 

While electrical and mechanical engineers will both need to gain a deeper understanding of each other’s domains, it would be even better to integrate these trade-offs directly into design software. This is similar to how we’ve already incorporated physics and materials data for impedance control calculations in ECAD field solvers, eliminating the need for electrical engineers to perform those calculations manually.

With the arrival of structural electronics, ease of design productivity will eventually demand integrated solutions. In the future, I see design environments where mechanical decisions immediately show electrical implications, and electrical choices affect structural performance.

Understandably so, multi-physics simulation has become standard practice, given realistic environmental challenges. Electromagnetic field solvers are coupled with mechanical stress analysis to get the full picture. We have thermal modeling that accounts for both electrical power dissipation and mechanical heating. Naturally, structural electronics will benefit from such multidisciplinary simulation for when we incorporate more structural electronics (kind of a mech-elec technology). With all these things to consider, one thing is for certain...

Design verification requires new methodologies and new software advancement. You can't optimize electrical performance without understanding mechanical constraints simultaneously.

What Mechanical Engineers Need Now

For mechanical engineers, the fundamentals fortunately remain the same. Stress analysis, material properties, and thermal management still apply. But as shown above, the context expands dramatically when it comes to structural electronics.

Material selection now includes electrical properties. Mechanical analysis must weigh dielectric constants, conductivity, and electromagnetic shielding effectiveness. These become just as important as mechanical strength and temperature resistance. In Kraig Mitnzer’s writings, he stated that mechanical properties and engineering take priority over electrical, as long as electrical performance is not negatively affected. 

Structural electronics increases the stakes so now the successful cooperation of electronics and mechanical will affect each other, so the priority and consideration hierarchy will undergo some more careful change and consideration before locking into a mechanical design.

Mechanical engineers will need to understand how dielectric constants affect signal propagation, how thermal expansion influences electrical parameters, and how mechanical stress alters component behavior. But where does one even begin to learn all of this?

The fastest way to make mechanical engineers aware is to start learning about impedance control. Understand why trace geometry matters for high-speed signals and signal integrity. Also learn how power distribution affects circuit performance and how spacing affects the electromagnetic field.

Designing the Future: When Structures Think

We're moving beyond electronics as separate components that are simply added to mechanical systems. While separate mechanical-electrical applications will continue to make the majority of electronic products, a future is making space for new products and materials that inherently combine mechanical and electrical functionality.

While this new technology presents challenges for engineering, it also creates opportunities for engineers who master both domains. New product categories become possible. Existing applications achieve capabilities that were impossible with only traditional approaches.

The transition requires new tools, new processes, and new ways of thinking about the relationship between structure and function. But the potential justifies the learning curve. Structural electronics enable smart, responsive systems that adapt to their environment and user needs in real-time.

The engineers who embrace this integration will define the next generation of intelligent materials and responsive structures.

Explore how Altium supports printed electronics and enables the integration of electrical circuits with three-dimensional mechanical parts.