Chirality, which denotes the absence of mirror symmetry, is ubiquitous in both inanimate and living systems. How to produce and control chirality is a fascinating problem in different disciplines of biology, chemistry, and engineering.
Chiral structures are commonly built by chiral molecules. Here, we show that achiral building blocks of a nematic liquid crystal can also produce chiral structures when the material flows in a microfluidic channel. This is a very rare phenomenon. Such flow-induced chirality provides a new way for obtaining spontaneous symmetry breaking, which may have potential applications in optical devices and for controlling assembly in biological systems.