  There are significant milestones in modern human's civilization in which
mankind stepped into a different level of life with a new spectrum of
possibilities and comfort. From fire-lighting technology and wheeled wagons to
writing, electricity and the Internet, each one changed our lives dramatically.
In this paper, we take a deep look into the invasive Brain Machine Interface
(BMI), an ambitious and cutting-edge technology which has the potential to be
another important milestone in human civilization. Not only beneficial for
patients with severe medical conditions, the invasive BMI technology can
significantly impact different technologies and almost every aspect of human's
life. We review the biological and engineering concepts that underpin the
implementation of BMI applications. There are various essential techniques that
are necessary for making invasive BMI applications a reality. We review these
through providing an analysis of (i) possible applications of invasive BMI
technology, (ii) the methods and devices for detecting and decoding brain
signals, as well as (iii) possible options for stimulating signals into human's
brain. Finally, we discuss the challenges and opportunities of invasive BMI for
further development in the area.
