A piezochromic material exhibiting a pressure dependent reversible shift of the selective reflection wavelength via the entire visible range is developed. The material consists of a cholesteric mixture embedded in a cholesteric elastomer matrix bearing mesogenic side chains with similar molecular structure. The change of the selective reflection has its origin in a compressible helix structure. Thus, the pitch length is switched by pressure changes. To trigger the reversible piezochromic effect already pressure changes in bar-range are sufficient. The pressure controlled colour changes are excellent detectable by the human eye and still appear even after 100 cycles.
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