Foldable phones could be hot – in more ways than one

The most fascinating thing about Apple's new iPhone Duo – and others like it – may not be that it folds.

<![CDATA[ <article> <p>The most fascinating thing about Apple's new <a href="https://www.techradar.com/news/best-iphone">iPhone</a> Duo – and others like it – may not be that it folds. It may be the innovation required to keep it cool. Because at a time when performance demands from edge AI continue to increase, we’ve now taken available smartphone real estate and – though not exactly halved it – constrained it more than ever. And that impacts heat. Which impacts performance.</p><p>What makes the Duo interesting isn't simply the engineering required to create a folding phone. It's that Apple is confronting the same challenge every edge device manufacturer now faces: AI capability is increasing faster than our ability to manage the heat it generates.</p><p>That’s why I believe we’re entering a new phase of device innovation, with thermal design increasingly shaping what’s possible. In the edge <a href="https://www.techradar.com/best/best-ai-tools">AI</a> era, managing heat helps determine what a device can do, how long it can sustain performance, and how small or thin it can be. </p><p>The iPhone Duo is just the latest reminder that <a href="https://www.techradar.com/news/best-business-smartphone">smartphone</a> manufacturers have run into a stubborn engineering problem: How to keep mobile processors cool when there’s almost nowhere left to put a cooling system. </p><p>For its part, with the Duo, Apple has packed its A20 Pro and other heat-generating electronics into an exceptionally thin, foldable design. It’s also created a custom vapor chamber to help dissipate heat and sustain performance in the new form factor. </p><p>The latter is more than an engineering footnote. It’s a glimpse at a challenge the edge AI industry is starting to confront. Thermal design and industrial design are inseparable. And new solutions to thermal challenges must be considered.</p><h2 id="foldables-make-the-challenge-obvious">Foldables Make the Challenge Obvious</h2><p><a href="https://www.techradar.com/best/best-foldable-phones">Foldable phones</a> make the thermal management challenge easy to perceive. Conventional smartphone design gives engineers a relatively predictable enclosure in which to arrange the processor, battery, cameras, and thermal management system. A foldable must accommodate a hinge and two display sections while remaining thin enough to fold comfortably and fit in a pocket. </p><p>At the same time, the processor and other electronics still generate heat – more, even, when we consider how people are starting to use mobile devices. Which means foldable designs necessarily concentrate significant heat-generating components into smaller and thinner portions of the device, precisely where space for thermal hardware is already constrained. </p><p>In general, vapor chambers remain one of the most effective ways to manage heat in a compact electronic device. They work by moving heat away from a concentrated source, such as a mobile processor, and spreading it across a larger area. But vapor chambers ultimately spread heat rather than remove it. </p><p>Sure, as processors become more powerful, manufacturers can increase the size and effectiveness of the vapor chamber. But eventually that thermal component itself becomes a design constraint, especially in foldable phones.</p><h2 id="agentic-ai-makes-the-challenge-urgent">Agentic AI Makes the Challenge Urgent</h2><p>In foldables, innovating around thermal management is itself an admirable design goal – if folding were the only technological advancement engineers had to tackle. But they’re pushing the envelope on physical design at the exact moment when smartphones are being asked to do much more. Namely, to process agentic AI workloads. </p><p>As agentic AI moves from the <a href="https://www.techradar.com/best/best-cloud-storage">cloud</a> to edge devices – AI-capable smartphones, wearables, glasses, and more – thermal management becomes the industry's most important challenge. Imagine a new foldable smartphone with its own specialized thermal management system, designed to accommodate an innovative new form factor. Now imagine asking that foldable to process vast amounts of data differently than before. </p><p>Unlike traditional <a href="https://www.techradar.com/best/best-mobile-app-development-software">mobile apps</a> that perform discrete tasks, AI agents operate continuously. They sense their environment, preserve context, analyze streams of <a href="https://www.techradar.com/pro/best-data-removal-services-of-year">data</a>, and act in real time. </p><p>In my view, the industry is still underestimating how significant this transition will be. Historically, a smartphone's thermal profile was defined by short bursts of activity: launching an app, streaming a video, capturing a photo. Agentic AI at the edge changes that model entirely. Devices are moving toward persistent intelligence, continuously sensing, processing, reasoning, and responding. With these sustained workloads, a device’s ability to manage heat becomes a defining constraint on its performance. </p><p>Passive thermal technologies remain indispensable. Vapor chambers, graphite, heat spreaders, and advanced materials will continue to play a critical role in future devices. The challenge is that Edge AI introduces thermal loads that increasingly benefit from more than heat spreading alone. As devices become thinner and workloads become more persistent, designers will need additional ways to not just to move heat away from sensitive components, but to move heat out of the system entirely.</p><h2 id="micro-cooling-complements-the-vapor-chamber">Micro-Cooling Complements the Vapor Chamber</h2><p>So here we are, with foldable smartphones capable of agentic AI processing. It’s a perfect storm of thermal design challenges. Engineers can continue enlarging or customizing the thermal systems they integrate into new and different form factors. Or they can find other ways to extract more thermal performance from available space. </p><p>The latter approach is where active, micro-cooling technology becomes a viable and important solution. </p><p>Unlike miniature rotary fans, which exist today and take up precious real estate of their own, MEMS-based piezoelectric actuators, fabricated in silicon, generate airflow inside extremely compact packages. Basically, it’s a fan on a chip, capable of precise active cooling that fits where conventional solutions cannot. </p><p>With micro cooling (µCooling), heat isn’t just spread out, it’s removed from the device entirely before it can sink into the case, delaying or eliminating thermal throttling. This hybrid approach to cooling in highly constrained spaces delivers better thermal performance in today’s AI-enabled smart devices. </p><p>It also creates greater design flexibility – a must as devices themselves become more physically flexible. If active µCooling can provide additional thermal performance, manufacturers may not need to maximize the physical dimensions of vapor chambers. A more appropriately sized, passive thermal system could be paired with localized active µCooling and thereby free up internal volume for other components and give designers more flexibility in how a device is assembled. </p><p>Put simply, with µCooling, thermal hardware wouldn’t have to consume as much of a device’s design envelope.</p><h2 id="cooling-as-part-of-the-compute-architecture">µCooling As Part of the Compute Architecture</h2><p>The implications extend beyond folding smartphones. AI glasses, <a href="https://www.techradar.com/audio/headphones/the-best-headphones">headphones</a>, watches, robots, and other edge devices face the same fundamental problem, often with even tighter constraints on size, weight, and power. </p><p>The industry wants to put more intelligence into mobile devices while simultaneously making them smaller and more comfortable. That creates a physical contradiction. More compute generates more heat. Smaller devices provide less room to manage it. </p><p>µCooling offers a way to change the equation. Not by eliminating vapor chambers and other passive solutions, but by supplementing them with localized active cooling that provides additional thermal headroom while giving product designers more freedom. </p><p>As AI runs more continuously in the background, edge devices will spend more time computing and less time idle. Sustaining performance will matter as much as reaching peak capability. Foldable phones make this challenge acute, but it extends across the edge AI market as more intelligence and local processing place greater demands on compact hardware.</p><p>That intelligence has a thermal cost. Over the next decade, progress will depend as much on what physical devices can sustain as on what AI models can do. That’s why I believe thermal management is becoming a foundational technology of the edge AI era. The companies that solve this challenge will help define the next generation of intelligent devices. </p><p>Manufacturers already know this, which is why thermal management is so essential to product design. µCooling is the innovation behind the innovation – like smartphones that fold.</p><p><em></em><a href="https://www.techradar.com/best/best-product-management-apps-of-year"><em>Check out our list list of the best product management software</em></a><em>.</em></p><p><em>This article was produced as part of </em><a href="https://www.techradar.com/pro/perspectives" target="_blank"><em>TechRadar Pro Perspectives</em></a><em>, our channel to feature the best and brightest minds in the technology industry today.</em></p><p><em>The views expressed here are those of the author and are not necessarily those of TechRadarPro or Future plc. 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