Semiconducting Silicone Enables Wearable Displays

While classic materials like glass, ceramics, and plastics have reliably served as insulators for decades, the rise of flexible, stretchable, and wearable electronics is pushing these traditional heroes to their limits. To keep up with modern demands, researchers are now looking beyond established norms to discover new insulating materials that are not only durable and heat-resistant but also compatible with next-generation electronics.

But what makes this search so difficult? Why are traditional insulators no longer enough, and what role could cutting-edge materials like semiconducting silicone play in redefining what an insulator can be?

The Challenge of Finding New Insulators

Insulators are the unsung heroes of electronics, standing between us and the uncontrolled flow of current. While their job may seem unglamorous, without them, any circuit would be a recipe for disaster, leading to short circuits, compromised device performance, and diminished reliability.

Over the past 100 years, some of the most trusted materials, such as glass, ceramics, and plastics, have kept things under control. But these tried and tested materials are being replaced with newer technologies: specialised polymers that resist heat, silicones that withstand high temperatures, and even whisper-light aerogels.

Yet, like all heroic materials, insulators can fail. Classic ceramics and glass are as brittle as bone when heated to extremes. Plastics, even advanced polymers, may not maintain the flexibility needed for stretchable, wearable, and foldable products. Even constant exposure to UV rays or moisture can severely affect performance, allowing unwanted currents to sneak in and cause harm.

Sadly, finding new insulators is not a walk in the park. Identifying materials that resists electricity, heat, aggressive chemicals, and physical punishment is a constant battle for researchers. Many promising materials demonstrated in the lab face all kinds of challenges; either they don’t work well with existing manufacturing processes or are simply too expensive.

With the future in sight, the bar for insulators is constantly being raised. Thankfully, we are entering an age where computational models and AI sift through millions of scenarios to help researchers find the most promising candidates. As such, the job of finding new insulators is not just a job for chemists; materials scientists, engineers, and visionaries must also work together. 

University of Michigan Researchers Discover Semiconducting Silicone with Flexible Electronics Potential

A team of researchers from the University of Michigan have discovered a new type of silicone that can conduct electricity, a property not previously associated with this category of materials. The findings, published in the latest edition of Macromolecular Rapid Communications, could provide new opportunities in the field of flexible electronics and wearable devices.

Silicones are commonly used as insulating materials in biomedical devices, sealants, and electronic coatings, and have been heavily prized for their ability to resist electrical and thermal conductivity. However, researchers from the University of Michigan discovered that a specific silicone copolymer has semiconducting properties as a result of changes in molecular bond angles between silicon and oxygen atoms.

“We have demonstrated a new method for allowing electrical conductivity by increasing the Si–O–Si bond angle in the silicone copolymer’s molecular structure, allowing better orbital overlap between silicon and oxygen atoms,” said Richard Laine, corresponding author of the study.

The material under investigation is a copolymer material that contains both cage-like silicone and linear silicone. The researchers discovered that the bond angle between Si–O–Si when in its ground state is 140°, and this bond angle is 150° when in an excited state. This angular shift allows for the two electron orbitals to overlap, and this provides the material with a conduction pathway.    

“Longer polymer chains reduce the energy required for light emission, enabling color tuning,” Laine said.

By manipulating the length of the polymer chains, the researchers demonstrated the ability to control the wavelength of emitted light, and thus, the colour. Longer chains emit less energy (red), while shorter chains produce more energy (blue). This is not the case with standard silicone materials, which are either colourless or white due to the lack of light absorption.

According to the lead author of the research, Zijing (Jackie) Zhang, a doctoral student in materials science and engineering:

“We’re taking a material that everybody thought was electrically inert and giving it a new life, one that could power the next generation of soft, flexible electronics.”

The new discovery could lead to new applications, including flexible photovoltaic panels, flat panel displays, wearable sensors, and textiles that have integrated visual capabilities. While the discovery of semiconducting silicone is still in its infancy, the ability to create semiconducting silicone not only shows promise for future electronic applications, but also in the field of light and colour.

Silicones in Electronics: The Next Leap?

Silicones have always been trusted for what they are not: conductors of electricity. Their role in electronics has been passive but important, providing the invisible barrier that keeps circuits in place, safe, and dry. However, this new discovery by researchers at the University of Michigan has demonstrated that silicone may be much more capable.

They have rethought a material that was once believed to be electrically inert and have potentially opened the door to a new category of semiconductors, semiconductors that are soft, flexible, and tunable. This could be particularly beneficial in a world that is moving toward wearable, stretchable, and even foldable electronics. In contrast, traditional semiconductors are rigid and fragile, making them limited for conformal and dynamic applications. A silicone-based semiconductor can provide both electrical and mechanical properties, thereby bridging a long-standing gap in material performance.

Furthermore, the research shows other advantages. The same molecular structure that makes the silicone conduct electricity also enables it to emit light in controllable ways. The researchers were able to control the length of the polymer chain to adjust the wavelength, and thus the colour, of the light produced across the visible spectrum. This could lead to completely new display technologies or even textiles that can change their colour and/or pattern depending on electrical input.

The new type of semiconducting silicone could also help simplify some designs, reducing the number of materials needed. Instead of needing to use a flexible insulator over a brittle conductor or relying on complex coatings, designers may be able to use a single material that does it all. This may be a major advantage in applications involving soft robotics, biomedical sensors, and flexible solar panels.

However, there are still questions to be answered:

• What is the durability of such a material under long-term use?
• Could it withstand the wear and tear of everyday environments?
• Could it be economically viable at scale?

These challenges remain, and further research needs to be done before semiconducting silicone can be widely deployed. However, with computational tools, simulation models, and lab technologies becoming more advanced, the possibilities are becoming increasingly promising.

If silicone can be reimagined as a semiconducting material, it may lead to similar advancements in other “inert” materials. But what else have we missed? What other workhorse substances might be underestimated?

As such, the real impact of this research may not be in the silicone alone. This is a reminder that innovation does not come solely from creating something completely new, but from seeing something familiar in a different way.