A Kenyan-built robotic arm is helping deaf students access science and technology lessons that teachers say are often difficult to deliver in sign language due to limited vocabulary for technical terms.

At Machakos Secondary School for the Deaf, learners are using a system developed by Nairobi-based startup ZeroBionic that converts spoken words into sign‑language gestures using an electronically controlled arm. The device is paired with a sensor‑fitted suit worn by teachers or demonstrators to record sign movements and feed them into a growing sign‑language database.

Teachers and developers say many scientific concepts do not exist in Kenyan Sign Language, leaving instructors to improvise and creating inconsistencies across schools. The new tool allows teachers to programme standardised signs for lessons, reducing confusion and helping students keep pace with STEM content.

The robotic arm, built partly from recycled plastics turned into 3D‑printing filament, mirrors hand shapes and finger positions shown on a classroom screen. It can also be operated remotely, allowing teachers to deliver lessons from other locations, including schools with limited internet access.

Chris Mwakala, a student testing the system, said the technology made complex material easier to understand. “You can be able to understand much better. You feel happy in school when teachers are using robots,” he said through an interpreter. ZeroBionic founder Maxwell Opondo said the suit records precise signing movements that the system can store and replicate through the arm.

Developers say more than 500,000 students have taken part in pilots and outreach programmes involving the system. The technology is also being tested in Switzerland, while similar projects exist in countries such as France and Vietnam.

Students and teachers in Machakos say seeing the device built locally has changed perceptions of engineering careers. “They see it’s doable here in Kenya, not just abroad,” Ayoyi said.

Production: Nelson Aruya, Edwin Waita, Mukelwa Hlatshwayo/Reuters