Invitro Synthesis of Microlens Arrays

A team of researchers at the Max Planck Institute of Colloids and Interfaces, together with multiple university partners, developed a simple synthesis process for microlens arrays, unique micro-optical devices.

The partners of Max for this initiative include the KAIST in South Korea, University of Konstanz, and the Korea Institute of Geoscience and Mineral Resources. The scientists used saturated calcium solution and CO₂ in air, which following mineral precipitation resulted in the synthesis of hemispherical, micro-optical CaCO₃ structures. The organic surfactant acted as regulatory elements.

Biominerals grow in aqueous media, in a genetically programmed series, at ambient conditions. The researchers revealed the rapid production of CaCO₃ structures with micron sizes on the surface of Ca saturated solution in atmospheric condition. In less than 2 h, a thin film is observed. Supplementing the growth media with organic surfactants enabled the synthesis of hemispherical- shaped and uniform-sized structures.

Multiple images of a µ-sized 'A' have been observed through the array of microlenses. The collimated light can be focused into1 µm spot by passing through 6 µm CaCO₃ microlenses with focal length ranges 7 - 8 µm.

This biocompatible CaCO₃ is included in the skeletons of a large number of biological organisms, where they act as substrates. The biocompatibility of the CaCO₃ microlens arrays can be determined by seeding fibroblasts, the common cells present in the connective tissue of animals. It also helps determine the viability of the cells on the array. Among the array, a single cell can cover multiple microlenses. This phenomenon represents that CaCO₃ microlens arrays combined with optics can be effectively used for cell biology research and analysis.