Disposable 3D printed Liquid sensor

A device for detecting liquid chemicals of various permittivity using a 3D Printed frequency selective surface (FSS) is proposed. The sensor is an array of square loops on a square unit cell with trenches dug in the dielectric material around the loops. The trenches allow deposition of the liquid chemicals to be detected. The variation in the dielectric characteristics of the liquids in the trenches produces a change in the resonance frequency of the FSS. Transmission coefficient is measured to evaluate the resonance frequency due to each liquid chemical. Butan-1-ol, Propan-2-ol, Ethanol and Methanol were added to demonstrate the sensing technique. Good agreement was found to exist between simulated and measured results. The envisioned detector could be used in a laboratory or in chemical industry where liquids can fall into the trenches for detection purpose. 3D printing allows for the rapid fabrication of the structure which can be disposable.