The event was held at the Odyssey Arena in Belfast and pupils from St Mary's Primary School, Banbridge Academy, Dromore High and Donard School were all involved.
Keen to show children the wide range of career opportunities in STEM fields, including the less traditional ones, John Spangler, vice president and managing director at Seagate's Springtown facility, said; "We are enthusiastic about being involved in Seagate Young Innovators as the event inspires the careers of the next generation.
"High tech companies like Seagate rely on a steady flow of graduates with STEM skills.
"It's good to see the vitality and enthusiasm that's generated when hundreds of young people, from 8 to 18 years, gather to compete.
"The challenges set in each category give young people a feel for science and engineering and can help them decide what subjects they should study at higher levels to help them along their career path."
Brian Campbell, chief executive of Sentinus, added: "Seagate Young Innovators involves young people working on STEM projects from a young age. It motivates and challenges them to look at the subjects in a new way.
"Many previous participants have gone on to take STEM courses at higher education level and have followed successful careers in engineering or science.
"That's what makes this our flagship event. It is an excellent example of how industry and education can work together in partnership."