Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Gravity Flow Micro-Physiological Article And Determining A Physiological Response To A Drug

Published Patent Application Numer: 2022/0134331 A1


The invention is a microphysiological system that is an open microfluidic multi-organ cell culture system. Fluidic flow is achieved with via gravity, and physiological fluid residence times are achieved by operating the device with a rotating platform at a particular speed. The device only contains near-physiological amounts of blood surrogate.  Since the device is open, oxygenation of the tissues cultured on the device is better than in closed microfluidic devices.

patent description

The invention is a gravity-operated microphysiological system that is open and that holds cell culture medium inside its fluidic channels via surface tension. The system uses gravity to drive fluidic flow, and a rotating platform or a rocking platform to control fluid residence times in its organ chambers, so it does not need a pump. Because the device is designed to be open, leaking is not an issue. Because the device is open, it does not need to be completely filled with liquid at all times, meaning that some parts of the fluidic circuits can remain empty for a period of time. This allows us to operate the device with physiologic amounts of liquid.  The device has the following: a fluid reservoir that is a mixing reservoir (# 203) from which blood surrogate flows into a fluid divider that divides up the liquid stream. From there, the partial fluid streams flow through the organ chambers (#202.1 to 202.10), where they come into contact both biological tissues. From the tissue chambers, the fluid streams flow back into the mixing reservoir, where they recombine. In that way, metabolites produced in one organ chamber will get redistributed into all other organ chambers. The flow is driven by gravity in one of two ways: the system can be placed at an angle onto a rotating platform. The rotation speed determines the fluid flow rate through the organ chambers and is set so that the flow rates are physiologic. The device can also be placed on a rocking platform that rocks it back and forth to change the direction of gravitational forces and drive fluidic flow.

Created September 21, 2022, Updated December 14, 2023