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Fabrication of humidity sensor using 3D printable polymer composite containing boron-doped diamonds and LiCl

journal contribution
posted on 2023-05-20, 22:07 authored by Umme Kalsoom, Waheed, S, Brett PaullBrett Paull

Humidity sensing is of significant interest to monitor and control the moisture sensitive environments. Here, we developed a novel 3D printable composite consisting of boron-doped diamond (BDD) (60 wt %) and LiCl (2 wt %) in acrylonitrile butadiene styrene (ABS). SEM analysis of the composite material confirmed the uniform distribution of the BDD and presence of a thin layer of LiCl distributed throughout the matrix. The developed composite material was employed for simple and quick (∼2 min) fabrication of the humidity sensor using low cost fused deposition modeling (FDM) 3D printer. The unique composite material allowed the fabrication of one-piece 3D printed sensor in comparison to traditional multicomponent (e.g., support, sensitive film, and electrodes) humidity sensing devices. The resulting humidity sensor showed excellent sensitivity with up to 125-fold change in resistance for the range of 11–97% relative humidity. The quick response (60 s, n = 3, RSD= 18.7%) and the recovery time (120 s, n = 3, RSD = 16.6%) is attributed to the uniform distribution of the BDD electrode material and strong networking with the LiCl layer distributed throughout the matrix. Long-term stability and repeatability was evaluated, with relative standard deviation of the response of less than 15% obtained over a test period of 14 days. When applied as a sensor for humidity in human breath, the response curves obtained for 12 consecutive breath cycles with post-breath compressed air-drying, showed excellent repeatability and sensitivity, with quick response and recovery (13 s, n = 12, RSD = 15%). The developed 3D printable humidity sensing material was also used to fabricate a customized 3D printed sensor for monitoring the humidity of the N2 supply.


Publication title

ACS Applied Materials and Interfaces










School of Natural Sciences


American Chemical Society

Place of publication

United States

Rights statement

© 2020 American Chemical Society

Repository Status

  • Restricted

Socio-economic Objectives

Composite materials