Theodorus Gerardus Jozef Jansen is a Dutch artist. In 1990, he began building large mechanisms out of PVC that are able to move on their own and, collectively, are titled Strandbeest. The kinetic sculptures appear to walk. His animated works are intended to be a fusion of art and engineering. He has said that "The walls between art and engineering exist only in our minds." Some of his creations are reported to incorporate primitive logic gates for collision detection with obstacles such as the sea.