Journal
ACS APPLIED ELECTRONIC MATERIALS
Volume 2, Issue 12, Pages 4146-4154Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsaelm.0c00942
Keywords
humidity sensor; carbon laser patterning; laser carbonization; carbon semiconductor; laser-induced graphene; sensing
Funding
- Max Planck Society
- Fonds der Chemischen Industrie
- German Federal Ministry of Education and Research [13XP5050A]
- Max-Planck-Fraunhofer cooperation (Glyco3Display)
- U.S. Department of Energy (DOE) [DE-AC36-08G028308]
- Solar Photochemistry Program of the Chemical Sciences, Geosciences, & Biosciences (CSGB) Division at the U.S. DOE Office of Science: Basic Energy Sciences
Ask authors/readers for more resources
A relative humidity sensor was produced by carbon laser patterning of a carbon precursor ink on a flexible substrate. Citric acid and urea, both inexpensive and naturally abundant molecules, are used as initial precursors to obtain a porous carbon foam after CO2 laser irradiation. The laser-patterned material is characterized by electron microscopy, Raman spectroscopy, and vertical scanning interferometry. An intrinsic p-type semiconducting behavior was confirmed by thermoelectric and Hall measurements. The resistance of this porous, metal-free material is sensitive to atmospheric variations, namely, temperature and relative humidity (approximate to 5 Omega.%). Under dry atmosphere, the sensor acts as a thermometer with a linear relationship between temperature and relative variation of resistance (0.07%.K-1). The evolution of the sensor resistance at different relative humidities and temperatures is studied by electrical impedance measurements. The kinetic transitory regime of water desorption from the carbonaceous surface of the sensor is analyzed using Langmuir's model. The equilibrium constant of adsorption K-ads has been determined, and the standard enthalpy of adsorption of water on the sensor surface is estimated at A(ads)H degrees = 42.6 kJ.mol(-1). The simple and inexpensive production and its high, stable sensitivity make laser-patterned carbon interesting for humidity sensing applications, and the method allows for the large-scale production of printed sensor arrays.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available