New Life for Outdated Electronics

Each year, over 1.2 billion smartphones roll off assembly lines—an energy-intensive process that consumes scarce resources and emits vast CO₂. Yet users replace still-functional phones every two to three years, often relegating them to recycling—or worse, landfills. Changing consumer habits alone is unlikely to slow this cycle, so researchers at the University of Tartu and international partners have explored a novel alternative: turning old smartphones into miniature data centers.

Associate Professor Huber Flores notes that innovation can stem from rethinking existing tools. His team, joined by Ulrich Norbisrath, Zhigang Yin, Perseverance Ngoy, and others, demonstrated that discarded handsets can be clustered into tiny, cost-effective processing hubs—at roughly €8 (a little over $9 USD) per device. Batteries are removed to prevent chemical leaks and replaced with external power supplies. Four phones are then housed together in 3D-printed casings, forming a compact prototype.

These micro data centers proved versatile. In urban settings, they could be installed at bus stops to tally passengers in real time, helping transit planners optimize routes. Remarkably, the prototype also performed underwater, automating marine surveys by counting sea life without human divers or post-dive video analysis.

By giving smartphones a second life, the project shows that outdated electronics need not become waste. With minimal investment and simple hardware tweaks, these devices can power sustainable digital infrastructures. As Norbisrath reflects, true sustainability involves reimagining today’s technology so that yesterday’s gadgets become tomorrow’s environmental solutions.