Microfluidic breath analyzer for detection of cannabis use in human breath
Project Grouping: Gas Detection
Detection of Tetrahydrocannabinol (THC) in breath has been used as an indicator of cannabis use. However, as there are traces of other volatile organic compounds (VOCs) in the breath, it is important to differentiate among different gases, and pinpoint the distinct “smell print” of THC. The general purpose Metal Oxide Semiconductor (MOS) gas sensors are sensitive and not selective to different gases. Micro-channels can be integrated with these sensors to enhance their selectively. However, these microfluidic gas sensors are not suitable for detection of large molecule gases (such as THC) as the diffusion process is slow and takes more than few minutes. In this project, a reliable and portable microfluidic-based breath analyzer for detection of cannabis in human exhaled breath is developed. The developed miniaturized device is capable of differentiating small concentrations of THC in the presence of other VOCs. This will be achieved through following objectives:
(1)Develop a gas sensor using a sensitive metal oxide semiconductor coupled with a selective microfluidic diffusion channel.
(2)Integrate the sensor with support systems for sampling, humidity control membrane, and sensor recovery module.
(3)Develop a microcontroller and data collection components to operate all the systems of the detector and to transmit data for analysis on portable devices.
(4)Conduct tests on human exhaled breath to optimize the device and address identified issues.
Ultimately, the proposed low-cost breath analyzer device provides a powerful tool for police roadside testing and also for personal monitoring purposes.
Allen O’Brien – Lab & Project Manager
Mohammad Paknahad – PhD Student, Technical Lead
Matthew Barriault, MSc Student
Pouria Mehrabi – MSc Student
Jannat Singh Bachhal – Undergraduate Student
Carmen Mcintosh – Undergraduate Student
Hannah Gomes – Undergraduate Student
Abigail Logel – Undergraduate Student
List of recent publications:
 M. Paknahad, J. S. Bachhal, A. Ahmadi, and M. Hoorfar. “Highly selective multi-target 3D-printed microfluidic-based breath analyzer.” In 2016 IEEE 29th International Conference on Micro Electro Mechanical Systems (MEMS), pp. 905-908. IEEE, 2016.
 M. Paknahad, J. S. Bachhal, A. Ahmadi, and M. Hoorfar, “Characterization of channel coating and dimensions of microfluidic based gas detectors” Sensors and Actuators B: Chemical, vol. 241, pp. 55-64 , 2017.