Ultrasonically manufactured microfluidic device for yeast analysis

We present a polycarbonate-based microfluidic device that was rapidly manufactured by ultrasonic hot embossing and welding. The fabrication of microstructures using ultrasonic processing allowed the embossing of micrometer-sized structures in polymer films by molding from a master die; this process was completed within seconds. The short manufacturing time required using this process and its ease of reproducibility allows rapid prototyping of custom-made microfluidic devices. Through ultrasonic fabrication, disposable microfluidic devices were newly designed and manufactured within a working day. The feasibility of these devices was demonstrated by cultivating yeast cells. The cells remained viable within this system for at least 22 h. Enhanced green fluorescent protein (eGFP) expression was initiated by providing the cells with a supply of the inducer galactose. The present study not only shows the potential of microfluidic devices fabricated by ultrasonic processing but also discusses their capability for use in microbial analysis.