Researchers Make 3D Flower With Interactive Chirality Selection [LOOK]

Hanyang University researchers have recently developed a dynamic chirality selection three-dimensional (3D) microarray.

Chirality is a quality of structure that cannot be overlaid, Phys.org said. For instance, even if the left and right hands appear identical in a mirror, the left hand cannot be superimposed on the right.

Biochemical research on chiral structures has been done to find medications that bind to DNA proteins. Chiral structures have been artificially fabricated for usefulness derived from chiral selectivity. Nevertheless, dynamic chirality switching is challenging.

Chiral Selectivity

The first work to show the on-demand and dynamically regulated chiral selectivity of a 3D microstructure was published in ACS Nano and inspired by a flower's corolla. The chirality of the flower corolla, frequently apparent, inspired the researchers. The chirality of Mandeville's five-petaled corolla helps the flower defend itself from strong winds. This chiral corolla has asymmetrically formed petals and a counterclockwise directionality. In contrast, flowers without chirality include Phlox subulata, which has a five-petal corolla with symmetrically formed petals that mirror each other. The term for this is achirality.

Five semicylindrical micropillars are radially aligned to resemble a genuine flower with five petals in a flower corolla-inspired 3D microstructure. This microarray's symmetrically formed semicylindrical micropillars make it an achiral structure. This work's important finding is that the microarray's achirality may dynamically vanish by twisting the micropillars, which changes the microarray's symmetrical form into an asymmetrical one.

The micropillars are made of magnetic iron particles and readily flexible polydimethylsiloxane, which causes the pillar tops to twist when a magnetic field is applied while the pillar bottoms stay fixed to the microarray substrate. The microarray does not superimpose with its mirror counterpart when the twisting actions begin.

As a result, clockwise or counterclockwise twisting actions cause the microarray's achirality to switch in real-time to a clockwise or counterclockwise chirality. Counterclockwise chirality results from the simultaneous clockwise twisting of micropillars arranged in an array. Micropillars that concurrently twist counterclockwise, on the other hand, lead to clockwise chirality.

How Structure Interacts With Polarity

Researchers in the paper, per News Archive, said underline a crucial feature of this technology, which is the ability to dynamically change the chiralities of the microarrays from counterclockwise to clockwise directionality and vice versa by merely controlling the direction of magnetic fields.

There may be uses for this chiral-selective three-dimensional microstructure in creating optical devices. The chirality of the structure interacts with circularly polarized electromagnetic waves of light, which can be either right- or left-polarized.

As light enters the chiral microarray, the chiral-selective interaction detects arbitrary light's polarization direction. The chirality of the microarray that resembles a flower corolla will selectively interact with either right- or left-circularly polarized light.

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