The Loomia Electronic Layer Vs. Printed Electronics

Electronic textiles (e-textiles) integrate electronics into fabric and textile materials, enabling capabilities like sensing, lighting, heating, and more in soft and flexible form factors. There are several technology approaches for developing e-textiles, with two major options being printed electronics and electronic layer assemblies like The Loomia Electronic Layer (LEL).

Both technologies have their unique advantages and disadvantages when it comes to factors like performance, scalability, ease of integration, and customization. In this article, we will explore The Loomia Electronic Layer technology in depth and compare it across multiple facets with printed electronics.

What is The Loomia Electronic Layer?

The LOOMIA Electronic Layer (LEL) is an award-winning e-textile circuit technology developed by Loomia. It is a soft, flexible printed circuit board that can be integrated into textiles and fabric goods to enable functions like heating, lighting, and more.

Some key things to know about the LEL:

●     Ultra-thin, lightweight, and flexible form factor

●     It can be sewable and bondable into textiles and fabrics

●     Customizable circuitry design, shape/size, and functionality

●     Handles flexing, bending, and stretching without damage

●     Provides higher performance than printed inks

●     Scalable manufacturing process (up to 20K units per week)

The LEL aims to overcome the limitations of conventional printed electronics while enabling easy integration into soft goods and textile products across industries like automotive, outdoor gear, and medical devices.

Printed Electronics Overview

Printed electronics refers to manufacturing processes where functional electronic inks and materials are deposited onto substrates using methods like screen printing, inkjet printing, and aerosol jet printing. These conductive, insulating, and semiconductor inks can be printed onto flexible substrates like fabric and film to create simple electronic circuits and devices.

Some benefits of printed electronics include:

●     Ability to print directly onto textile fabrics

●     Simple and low cost for simple circuitry

●     Highly scalable with roll-to-roll production

●     Can cover very large surface areas

However, printed electronics also come with some downsides:

●     Typically, lower performance than integrated circuits

●     Inks can crack and degrade conductivity over time/use

●     Requires protective overlays, adding thickness

●     Design and patterning limitations

For these reasons, a more complex circuity with high-performance requirements is better suited to electronic layer assemblies.

LEL Vs. Printed Electronics - Learn the Difference

Flexibility & Conformability

One of the major benefits of both printed electronics and the LEL is their ability to flex, bend, and conform to surfaces without losing functionality. This level of mechanical flexibility allows integration into wearable devices, automotive interiors, and other applications where rigid PCBs would fail.

The LEL provides extremely high flexibility and drapability exceeding that of most flexible PCB options. In standard flex tests, LEL samples can bend to a 5mm radius hundreds of times without conductive degradation. This allows the LEL to conform smoothly to curved surfaces and maintain close contact during product integration.

Inks and conductive materials used in printed electronics can also flex well initially. However, common functional inks like silver can develop micro-cracks over time when flexed repeatedly, raising resistance substantially. Additional protective layers are often required to prevent this cracking but add thickness and stiffness.

In summary, while both technologies provide good flexibility, the LEL maintains higher flexibility and conforms better to surfaces and shapes.

Performance & Reliability

When it comes to factors like conductivity, heating efficiency, antenna performance, and reliability, the LEL provides markedly higher performance than printed electronics options.

The LEL utilizes a structured conductive foil trace layout, allowing an extremely low resistivity of 0.03 ohms/square. This permits high currents necessary for functions like resistive heating without voltage drops across large-area circuits. Printed silver inks typically have much higher resistivity, limiting the current capacity for similar voltages.

Heating testing shows that LEL foil traces produce 30-40% more efficient heating compared to printed silver inks. Antenna testing demonstrates 40% higher radio frequency performance for the LEL over printed antennas.

The reliability of printed traces degrades as ink layers crack from repeated flexing and environmental exposure. LEL foil traces encapsulated in thermoplastic polyurethane films provide lasting performance without degradation over product lifetimes.

So, for applications requiring the highest levels of efficiency, conductivity, and reliability, the LEL substantially outperforms printed electronics solutions.

Design Complexity Limitations

A key benefit of the LEL technology is the ability to create intricate and complex circuit layouts that are not possible with printing techniques. Conductive traces can be designed with extremely high precision, and components can be closely positioned in optimized layouts.

The printed electronics design space is much more constrained by the resolution limits of printing equipment (inkjet, screen printing, etc). Multi-layer circuitry with isolated crossovers is also extremely difficult and cost-prohibitive with printing methods. This severely restricts opportunities for customization and optimization.

Additionally, printing directly onto textile fabrics presents challenges around ink bleed, layer-to-layer registration, and material handling that make high precision patterning very difficult. The LEL assembly process removes these issues by printing onto known good substrates.

So, while printing does allow some basic customization, the LEL enables far more complex and application-specific circuit designs.

Reliability and Product Lifetimes

Ensuring reliable functionality over the entire operating lifetime is critical for mass-produced electronics in automotive, consumer goods, and medical products. Repeated environmental and mechanical stresses can degrade printed electronics over time.

The LEL encapsulates printed foil traces between flexible polymer films, securing traces from displacement or corrosion even after repeated bending and twisting. LEL test samples flexed over 20,000 times to a 4mm radius showed no electrical or mechanical failures.

Alternatively, ink layers in printed electronics can begin cracking from just hundreds of flex cycles as conductive particles separate. As cracks propagate, resistance increases steadily, reducing current flow. Harsh environmental factors also degrade prints further over product operation.

The LEL provides inherently higher reliability over printed electronics under mechanical and environmental stresses associated with textiles.

Manufacturing Scale Limitations

Developing any new product for mass production requires manufacturing processes that ensure high product quality, yields, and volume scalability without exploding costs. Both LEL assemblies and printed electronics aim for production scalability.

The LEL leverages widely adopted PCB manufacturing methods, enabling production on dedicated SMT assembly lines optimized for flex circuits. LEL partners like Eastprint currently support up to 20,000 devices per week. The global PCB industry has a tremendous capacity for scaling up if needed.

However, ultra-high volume production suits roll-to-roll style manufacturing. For products only requiring very simple circuity, printing has the potential for larger volumes and lower costs. However, material and handling challenges with textile printing complicate reaching extreme scales reliably.

So, while printing supports greater ultimate volume potential, LEL provides a faster path to medium/high production levels with proven manufacturing ecosystems.

Component Integration Capabilities

The LEL provides vastly superior support for integrating off-the-shelf electronic components into circuit designs. The PCB-based manufacturing process enables populated component placement into the layer using standard SMT equipment before encapsulation. This permits incorporating ICs, sensors, connectors, and other discrete parts at specific optimized layouts within a layer.

In contrast, printed electronics processes are constrained to simple deposition of layered inks onto substrates. There is little to no capacity for the placement of pre-built components into a design. All circuitry and devices must be directly printed, greatly limiting the complexity and functionality possible. The only option is to attach separate components onto the surface, leading to reliability challenges.

Repairability and Replaceability

A key advantage of the modular design in LEL assemblies is the ability to easily repair or replace individual components if needed after deployment. Damaged sections or non-functioning parts can be swapped out without scrapping an entire device.

However, with printed electronics, it is not feasible to repair failed sections or traces. A single short or open trace can quickly render an entire printed circuit non-operational. For this reason, durability and reliability are paramount. Repairing failed traces in the field is extremely difficult, if possible at all. This limits sustainability and leads to greater waste.

Bridging Between Rigid & Soft Materials

Making reliable connections from soft circuits to rigid component terminals is tremendously difficult, requiring careful strain relief design. The LEL incorporates specialized patented methods for securely and consistently making these “hard-soft” interface bridges to connectors, cables, PCBs, and other incompatible materials.

This specialized capability simply does not exist with printed electronics. Integrating off-the-shelf inflexible electrical components with printed soft circuits is an unsolved challenge. Additional handling, cabling, and protective coverings are necessary whenever spanning between the two very distinct material types.

Conclusion

In reviewing key e-textile technology options between printed electronics and the Loomia Electronic Layer, each provides unique advantages and tradeoffs.

For applications only requiring very simple sensor circuits or heating elements, printed electronics provide a path to low-cost production. However, more complex performance with demanding performance requirements benefits much more strongly from the advanced capabilities of the Loomia Electronic Layer technology.

Both technologies continue advancing to power e-textile integration across diverse industries and products. However, the LEL has demonstrated performance and reliability exceeding existing printed electronics capabilities available today. As material and process innovations emerge in printed electronics, it will be exciting to follow the convergence of these technologies toward fully unlocking smart fabric applications.