The History of Biochips

A biochip is essentially a biomedical lab miniaturized and contained on a single chip. Biochips vastly increase the speed at which biomedical analysis can be carried out, performing thousands of simultaneous biochemical reactions. Best known for speeding up the process of DNA analysis, biochips can shorten the time it takes to get results from a number of chemical tests and will one day be implantable, so it will be able to carry out laboratory tests from within the human body. Advances in both biomedical detection methods and in microminiaturization of components from the semiconductor industry contributed over time to the evolution of the biochip.

Chemical Sensors

• Biochips must be able to sense chemical qualities of the samples they test. The development of chemical sensors that could be miniaturized was the first step toward developing the biochip. In 1922, W.S. Hughes invented the first such sensor, called a glass pH electrode, which used chemical exchanges in a thin glass membrane to detect a substance's pH level. Over the next several decades chemical sensors were developed to detect levels of oxygen, glucose and other substances.

DNA

• In 1953, Watson and Crick famously discovered the double helix structure of DNA. By 1977 scientists had developed DNA sequencing techniques. In 1983 Kary Mullis invented the polymerase chain reaction technique, which amplified DNA concentrations, allowing scientists to detect DNA in very small quantities within a sample.

DNA Sensors

• The subsequent development of biochip DNA sensors incorporating these techniques allowed biochip technology to be a crucial part of mapping the complete human genome. Today, biochips are regularly used to sequence not only individual DNA samples but to quickly sequence bacteria and virus DNA in order to quickly develop vaccines.

Semiconductor Microminiaturization

• Biochips rely heavily on the miniaturization techniques developed by the semiconductor industry. A biochip is an array of chemical sensors linked together that can convert data into a computer readable form. Technologies for miniaturizing the circuitry to both connect the sensors and for converting data was developed throughout the 1980s and commercialized in the 1990s.

Implantable Biochips

• Work in the first decade of the 21st century by scientists at Clemson University has introduced the possibility of an implantable biochip. The chip, about the size of a grain of sand, is coated in a special gel to keep the body's immune system from rejecting it and is designed to deliver instant data about injured soldiers' oxygen and glucose levels on the battlefield.