If you’ve ever built a Raspberry Pi project, logged sensor data with Arduino, or experimented with time-lapse rigs, chances are you’ve got a few microSD cards lying around - maybe in a drawer, maybe in a plastic box you keep meaning to label. Each card is barely the size of a fingernail. Each weighs just two grams. And each might hold the key to empowering a woman you’ll never meet.
That’s the idea behind SD4Africa - a project from the Audiopedia Foundation that turns tech excess into life-changing knowledge delivery. It’s not about recycling for recycling’s sake. It’s about putting forgotten hardware back to work in the most direct, human way possible.
Since their introduction, over 12 billion SD and microSD cards have been manufactured. The SD Association itself estimates that about 60% of those cards are now sitting unused - tucked into drawers, boxes, closets, forgotten. That’s roughly 7.2 billion pieces of untapped potential, each one capable of holding hours - thousands of hours - of spoken knowledge.
Meanwhile, in many parts of sub-Saharan Africa and South Asia, half a billion adult women still can’t read. That number hasn’t changed much in decades. And when you can’t read, nearly everything we take for granted online - YouTube videos, PDFs, health tips via text - is inaccessible.
But audio? Audio is universal. It doesn’t require a screen. It doesn’t need a literacy level or an internet connection. It just needs a speaker - and in many places, basic feature phones with microSD slots are everywhere.
SD4Africa works like this:
One tiny card. One basic phone. A ripple effect of knowledge.
This isn’t a theory - it’s been tested.
In a 2021 pilot project in Nigeria, 503 women were split into three groups. One received Audiopedia content via WhatsApp, one via preloaded microSD cards, and the third received no intervention. The results?
The group using microSD cards improved their health knowledge scores from 63% to 100% in just a few weeks - on par with the WhatsApp group, despite having no internet access at all.
Even more impressive? Many of the women shared the cards with others. Some played the lessons while doing chores, while others formed small listening groups. The reach of a single card multiplied.
microSD cards don’t just hold data - they hold emissions.
According to lifecycle analyses (such as Samsung’s Carbon Trust–audited assessments), each card produced carries an embodied carbon footprint of approximately 13 kg of CO₂ equivalent. By repurposing existing cards, SD4Africa not only delivers knowledge - it avoids new manufacturing emissions and diverts plastic from landfills.
One card might not seem like much. But five cards reused = 65 kg CO₂ saved. And when multiplied across thousands of donors, the climate impact adds up fast.
This isn’t just a feel-good side project.
In 2023, the United Nations named Audiopedia the flagship gender-equality tech solution in its SDG Digital Acceleration Agenda - specifically recognizing SD4Africa for its ability to scale and reach the world’s most marginalized women.
The tech industry took note, too. To mark 25 years of the SD format, the SD Association donated $25,000 to help grow the initiative and endorsed the reuse model as a blueprint for meaningful circularity.
“We’re proud to support the empowerment of women through such a meaningful reuse of microSD cards.”
- Yosi Pinto, President & Chairman, SD Association
If you’re part of a makerspace, you probably already live and breathe the philosophy of repurposing. You take old tech, rewire it, reprogram it, turn it into something better. SD4Africa is that mindset, writ large.
Where others see e-waste, you see an opportunity.
Where others see plastic clutter, you see tools.
Where others shrug at a dusty card, you know it still works - and now, you know what else it can do.
Let’s do the math:
Multiply that by your desk drawer, your lab, your school, your community - and suddenly you’re part of a new kind of infrastructure.
An infrastructure of small, smart, quiet interventions that ripple outward.
One card at a time.
This is what SD4Africa is about: bridging tech abundance and knowledge scarcity.
Turning a storage device into a human device.
And giving makers like you a direct role in something quietly powerful.
Want to learn more? Visit makers.sd4.africa
Because even the smallest hardware can carry the biggest impact.