Kang, Han SolHan, Sang WonPark, ChanhoLee, Seung WonEoh, HongkyuBaek, JonghyeokShin, Dong-GapPark, Tae HyunHuh, JuneLee, HyungsukKim, Dae-EunRyu, Du YeolThomas, Edwin L.Koh, Won-GunPark, Cheolmin2020-10-302020-10-302020Kang, Han Sol, Han, Sang Won, Park, Chanho, et al.. "3D touchless multiorder reflection structural color sensing display." <i>Science Advances,</i> 6, no. 30 (2020) American Association for the Advancement of Science: https://doi.org/10.1126/sciadv.abb5769.https://hdl.handle.net/1911/109467The development of a lightweight, low-power, user-interactive three-dimensional (3D) touchless display in which a human stimulus can be detected and simultaneously visualized in noncontact mode is of great interest. Here, we present a user-interactive 3D touchless sensing display based on multiorder reflection structural colors (SCs) of a thin, solid-state block copolymer (BCP) photonic crystal (PC). Full-visible-range SCs are developed in a BCP PC consisting of alternating lamellae, one of which contains a chemically cross-linked, interpenetrated hydrogel network. The absorption of a nonvolatile ionic liquid into the domains of the interpenetrated network allows for further manipulation of SC by using multiple-order photonic reflections, giving rise to unprecedented visible SCs arising from reflective color mixing. Furthermore, by using a hygroscopic ionic liquid ink, a printable 3D touchless interactive display is created where 3D position of a human finger is efficiently visualized in different SCs as a function of finger-to-display distance.engThis is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.Journal articlehttps://doi.org/10.1126/sciadv.abb5769