The competition will be open to the public tomorrow.
Climate change will make up two-thirds of the projects at the BT Young Scientist and Technology Exhibition.
45 groups of students from the midlands will be setting up their presentations today, ahead of the opening ceremony by the Taoiseach this afternoon.
Social media and mental health also feature among the 550 exhibits at the RDS, which will all be open to the public from tomorrow.
BT Ireland Managing Director Shay Walsh says students feel nervous at the early judging stages: