Singapore – A 3D printed-polyurethane flower that blooms when exposed to sunlight has been created by scientists at Nanyang Technological University in Singapore. The polyurethane was made photoresponsive by mixing it with carbon black, which heats up when exposed to sunlight.
Polyurethane flower blooms in the sunshine

To gild refined gold, to paint the lily.
The heat generated on illumination activates the polyurethane’s shape recovery. This was demonstrated by 3D printing a sunflower that mimics the heliotropic behaviour of the flower, using a fused deposition modelling printer. When exposed to a xenon lamp or natural sunlight, the printed flower gradually blooms over a period of about five minutes.
The team speculate that this technology could have applications in the design and fabrication of biomimetic smart devices and soft robotics.
Reference: H. Yang et al. Adv. Mater. 2017, 1701627 (doi: 10.1002/adma. 201701627)