Discrete Chemical Release From a microfluidic Chip

Controlled chemical release has many applications, including treatment for diabetes and stimulation of neurons. In this paper we present a discrete chemical release method capable of delivering picoliter volumes of chemical solutions with 100 µ m spatial and 20 µ s temporal resolution. The releasing mechanism is based on the transfer of discrete picoliter sized liquid droplets from an ejecting nozzle to a receiving aperture, through an air-trapped hydrophobic chamber. This new method could be a key enabling technology for the precisely controlled release of biochemicals, like potent drugs and neurotransmitters, for modern clinical therapeutics and biological research.