Artificial flowers that bend their petals and fold when steeped in water are the latest demonstration of a trend that’s due to upstage 3-D printing for sheer gee-whiz factor.

It’s called 4-D printing. This concept steps beyond the three-dimensional shape and structure of an object typical of 3-D design to create smart materials that respond to the environment. By layering materials in different patterns, thicknesses, and shapes, engineers can create objects that will shape-shift over several minutes, as it is exposed to water, or air, or heat.

The eventual applications could include smart fabrics that change their weave in response to warmer weather.

The latest demonstration of this concept comes from the Harvard University laboratory of Jennifer Lewis, an engineering professor who has been finding ways to 3-D print hard-to-wrangle materials like living tissue and metals.

The self-folding flowers were designed by a team led by Lewis, and are made of a flexible polymer. During printing, the material is layered on in such a way that it forces the material to fold in a specific direction when water is added. In this case, the petals of a flower bend, the group explained in the journal Nature Materials on ­Monday.

Lewis is also the founder of Voxel8, a startup based in Somerville. Voxel8 is developing Lewis’ technology that prints plastic and metals to create ready-to-use gadgets and electronics. The company raised $12 million last year, and is among a handful of Massachusetts companies vying for a slice of competitive space.

Other labs, among them the Self-Assembly Lab at MIT, are also working on 4-D printing.

Nidhi Subbaraman can be reached at nidhi.subbaraman@globe.com. Follow her on Twitter @NidhiSubs.