IBM's one-step point-of-care-diagnostic test is based on a silicon chip that can test for many diseases, including cardiovascular. Following a heart attack, for example, the patient's serum or blood sample could be tested immediately to determine treatment and survival rate.

IBM Research - Zurich ( scientists Luc Gervais and Emmanuel Delamarche in collaboration with the University Hospital of Basel in Switzerland developed the diagnostic test that uses capillary forces to analyze serum or blood samples for the presence of disease markers, which are typically proteins that can be detected in people's blood for diagnostic purposes. Capillary action is the tendency of a liquid to rise in narrow tubes or to be drawn into small openings. An everyday example of a capillary action can be viewed by dipping a paper towel in a cup of water - the microstructures in the paper fiber enable the towel to absorb the water.

All in the chip

IBM scientists encoded the forces of capillary action on a microfluidic chip made of a silicon compound, similar to those used in computer chips, thus leveraging IBM's experience in developing and manufacturing silicon semiconductor wafers. The chip measures 1 × 5 cm and contains sets of micrometer wide channels where the test sample flows through in approximately 15 sec, several times faster than traditional tests. The filling speed can be adjusted to several minutes when the chip requires additional time to read a more complex disease marker.

The microfludic chip, which is based on nearly three years of research and development, consists of a microscopic path for liquids with five innovative stages:

Stage 1: A one microliter sample, 50 times smaller than a tear drop, is pipetted onto the chip, where the capillary forces begin to take effect.

Stage 2: These forces push the sample through an intricate series of mesh structures, which prevent clogging and air bubbles from forming.

Stage 3: The sample then passes in a region where microscopically small amounts of the detection antibody have been deposited. These antibodies have a fluorescent tag and like the antibodies within our body, they recognize the disease marker and attach to it within the sample. Only 70 picoliters (a volume one million time smaller than a human tear) of these antibodies are used, making their dissolution in the passing sample extremely fast and efficient.

Stage 4: The most critical stage is called the “reaction chamber,” which measures 30 µm in width and 20 µm in depth, roughly the diameter of a strand of human hair. In this stage, the disease marker that was previously tagged is captured on the surface of the chamber. By shining a focused beam of red light, the tagged disease markers can be viewed using a portable sensor device that contains a chip similar to those used by digital cameras, albeit this one is much more sensitive. Based on the amount of light detected, medical professionals can visually confirm the strength of the disease marker in the sample to determine the next course of treatment.

Stage 5: The capillary pump is less a stage and more a part of the entire process. It has a depth of 180 micrometers and contains an intricate set of microstructures, whose job is to pump the sample through the device for as long as needed and at a regular flow rate, just like the human heart. This pump makes the test accurate, portable, and simple to use. IBM scientists developed a library of capillary pumps so that tests needing a variety of sample volumes or test times can still be done without having to re-engineer the entire chip.

“This point of care test has achieved the trifecta for medical staff in that it is portable, fast, and requires a very small volume of sample,” says Emmanuel Delamarche, scientist, IBM Research - Zurich. “We are giving back precious minutes to doctors so they can make informed and accurate decisions right at the time they need them most to save lives.”

Going to market

The IBM research received support from KTI/CTI, an organization that fosters innovation in Switzerland. “This microfluidic chip is the next step in the evolution of point-of- care devices; we look forward to working with IBM Research - Zurich to develop this innovation even further,” says Thierry Leclipteux, chief executive officer and chief science officer, Coris BioConcept (, a Belgium-based biotechnology company developing rapid tests for diagnosis of enteric and respiratory pathogens.

Looking ahead, the chip can be embedded in several types of form factors, depending on the application, including a credit card, a pen or something similar to a pregnancy test. Besides diagnosing diseases, the test is also flexible enough to test for chemical and bio hazards.