Here's a picture of plans for a small kite. It is about the same size as the "Micron". For starters I will add remarks about building in this page, not in the picture...
The result could look like my home built Mini.
On the plans are the sail sizes, so you have to allow for the seams at the
bottom and the sail connecting edges. Leave some extra space for creating the
leading edge tunnels. The center part can be made in one peace (just mirror the
center piece part....)
I usually draw the curve of the leading and trailing edge using a piece of fiber/carbon. Fix it at one point. Use your hands to get the right curve, and draw the curve with your third hand...:-) The spine is not in a tunnel, it just fits between nose dacron and a piece of dacron at the bottom. The center T connector is one that is usually not used as a center T connector and in nother type of kite (forgot which one...). I drilled the spine hole (2mm). It allows the bottom spreader to be made in one piece since it sticks through the T part. It also keeps the spine and bottom spreader rather far apart (about 2 cm). There are multiple solutions to connect the spreaders to the leading edge spars. I used 2mm rubber caps (usually sold to protect the sail from the sharp edges of the whiskers carbon) and used them like you do the rubber hose in the larger kites. You can also make the spreaders a little longer (1.5 cm at each side) and let them stick out and use a rubber band.
There are also some dacron reinforcements at the wing tips, the leading-edge/spreader connections and the places where the whiskers meet the sail.
There are people that scaled this one up to a wingspan of 180 cm....
It seems to work fine. Only bridle adjustment is needed.