Tubular gas preconcentrators based on inkjet printed micro-hotplates on foil
This paper presents the design and implementation of a foil gas preconcentrator (FGP) based on a gold micro-hotplate inkjet printed on a polyimide (PI) substrate. The device is made on flexible foil using printing whereas all preconcentrators seen in literature are mainly based on rigid substrates and are micro-machined using cleanroom processes. Printing allows the additive and localized deposition of materials at low temperature on large area and can be applied to both the patterning of the heating element and the integration of the gas absorbent material. The benefits are the easy and flexible processing of cost-effective and lightweight preconcentrators for a variety of target gases. The tubular shape of the FGP is obtained by rolling up and sealing the inkjet printed gold hotplate on foil, which is then filled with the gas absorbent material (Carbopack B and Tenax). The diameter of the inlet/outlet of FGP is adjustable leading to high flow rates, up to 1.5 L/min, much larger than their silicon counterpart. The concept was validated using four target gases (benzene, toluene, nitrobenzene and acetophenone) at concentrations down to 250 ppb. For example, the duty cycle of the FGP was reduced down 1 min and a preconcentration factor of 200 was obtained after an adsorption on Carbopack B of 250 ppb of toluene during 2 min at 1 L/min. (C) 2016 Elsevier B.V. All rights reserved.