Aliza Shahid worked on acoustic amplification using a “Fresnel lens”. These are primarily used in optical applications but the IYPT student was asked to investigate its application to focus acoustic waves. The Fresnel lens was manufactured using the 3D printing facilty at Physlab. The design consisted of a flat lens composed of perforated air channels in the form of concentric rings. The sound waves diffract through these channels and undergo constructive interference creating a focal point where an amplified sound can be detected.