Abstract: A combination of capillary forces and gas pressure is used to control the movement of liquid samples within a microfluidic device. A liquid sample introduced to a proximal portion of a capillary channel of a microfluidic device moves by capillary action partway along the capillary channel. As the liquid sample moves, a pressure of a gas acting upon a distal gas-liquid interface of the liquid sample increases by an amount sufficient to stop further movement of the liquid sample. To initiate further movement of the liquid sample, a pump connected to a distal portion of the capillary channel decreases the pressure of the gas acting upon the distal gas-liquid interface of the liquid sample by an amount sufficient to permit the liquid sample to move by capillary action further along the capillary channel of the microfluidic device.

Abstract: A combination of capillary forces and gas pressure is used to control the movement of liquid samples within a microfluidic device. A liquid sample introduced to a proximal portion of a capillary channel of a microfluidic device moves by capillary action partway along the capillary channel. As the liquid sample moves, a pressure of a gas acting upon a distal gas-liquid interface of the liquid sample increases by an amount sufficient to stop further movement of the liquid sample. To initiate further movement of the liquid sample, a pump connected to a distal portion of the capillary channel decreases the pressure of the gas acting upon the distal gas-liquid interface of the liquid sample by an amount sufficient to permit the liquid sample to move by capillary action further along the capillary channel of the microfluidic device.

Abstract: The present invention relates to methods for joining materials as well as articles manufactured using such processes. The invention pertains to a process for joining a first substrate to a second substrate. The process includes irradiating a portion of a first substrate with a laser beam having a first wavelength and intensity sufficient to increase the absorbance of the first substrate to light having a second, different wavelength. The laser beam may carbonize at least a portion of the irradiated portion of the first substrate imparting a higher absorbance to light than non-irradiated portions of the first substrate. A second substrate is then placed in contact with the irradiated portion of the first substrate. The first substrate is then irradiated with a second laser having a second wavelength, different to the first wavelength; with a sufficient intensity to heat and, preferably melt, the irradiated portion of the first substrate.

Abstract: A combination of capillary forces and gas pressure is used to control the movement of liquid samples within a microfluidic device. A liquid sample introduced to a proximal portion of a capillary channel of a microfluidic device moves by capillary action partway along the capillary channel. As the liquid sample moves, a pressure of a gas acting upon a distal gas-liquid interface of the liquid sample increases by an amount sufficient to stop further movement of the liquid sample. To initiate further movement of the liquid sample, a pump connected to a distal portion of the capillary channel decreases the pressure of the gas acting upon the distal gas-liquid interface of the liquid sample by an amount sufficient to permit the liquid sample to move by capillary action further along the capillary channel of the microfluidic device.