These metal flowers open and close based on the temperature around them, in a process known as thermal expansion. A bimetal coil expands when it’s hot and contracts when it’s cold, allowing the flowers to act like their natural counterparts without electricity. Creator and Aerospace Engineer Greg Mathy from Bimetal Creations has a Kickstarter campaign for the flowers, which ends Wed. Aug. 12 and has raised more than $17,000. Four flower types are available now – Henrietta, Ruth, Ethel and Mabel. The flowers could make a drought-resistant garden, or be a welcome option for those without green thumbs.