Bruce Zhi Gao, Ph.D describes the characteristics of lasers. There are 2 meanings of laser: first, it is a device that generates a laser; second, there is an optical beam generated by this laser, which is comparable to light or sunshine. They have special characteristics which are described by Dr. Gao. Laser Tweezers uses a lance to focus the laser beam to a very small spot so it generates a very strong optical force. These are used to grab cell to move it, allowing us to see if can form a pattern to mimic the major structure of a tissue.