Rationally designed microstructures

The diversity, hierarchy, and complexity of mineralized architectures formed by living organisms seem virtually unlimited.

Microscopic acantharea up to reef building corals are able to precisely control the development of intricate mineral skeletons. Our aim is not so much to reproduce any particular shapes seen in nature, but to get to the root of what kind of physical and chemical principles might allow for such amazing control, and trying to adapt these ideas to design our own complex shapes.

Mineralization processes in living organisms continuously respond to environmental changes such as the temperature, CO2 concentration and acidity. Building on this principle, we dynamically modulate the environmental conditions in a beaker to actively steer mineralizing compounds into deterministic patterns. We have developed a comprehensive model for predicting the evolution of patterns a priori, and have used it to derive sequences of simple, subtle modulations of CO2, pH, and temperature that serve as building strategies for intricate higher-order nano/microarchitectures.

Using continuous and/or stepwise adjustments, we showed that the precipitating reactants can be steered into complex flowers, corals, vases, and messages, with precise control over placement of stems, leaves, etc. via sequential combinatorial assembly of the developing shapes.

Currently, we are further developing a detailed mathematical theory that predicts the emergence of the different shapes along with new experimental strategies that allow an even more precise manipulation of the growth conditions. This more and more refined control over the construction of micro architectures moves towards the control that is required for many practical applications, such as in optical materials, and catalysts.


Kaplan CN, Noorduin WL, Li L, Sadza R, Folkertsma L, Aizenberg J, Mahadevan L. Controlled growth and form of precipitating microstructures. Science. 2017;355 (6332) :1395-1399. Publisher's VersionAbstract

Controlled self-assembly of three-dimensional shapes holds great potential for fabrication of functional materials. Their practical realization requires a theoretical framework to quantify and guide the dynamic sculpting of the curved structures that often arise in accretive mineralization. Motivated by a variety of bioinspired coprecipitation patterns of carbonate and silica, we develop a geometrical theory for the kinetics of the growth front that leaves behind thin-walled complex structures. Our theory explains the range of previously observed experimental patterns and, in addition, predicts unexplored assembly pathways. This allows us to design a number of functional base shapes of optical microstructures, which we synthesize to demonstrate their light-guiding capabilities. Overall, our framework provides a way to understand and control the growth and form of functional precipitating microsculptures.

Noorduin W, Grinthal A, Mahadevan L, Aizenberg J. Rationally Designed Complex Hierarchical Microarchitectures. Science. 2013;340 :832-837. Publisher's VersionAbstract
The emergence of complex nano- and microstructures is of fundamental interest, and the ability to program their form has practical ramifications in fields such as optics, catalysis, and electronics. We developed carbonate-silica microstructures in a dynamic reaction-diffusion system that allow us to rationally devise schemes for precisely sculpting a great variety of elementary shapes by diffusion of carbon dioxide (CO2) in a solution of barium chloride and sodium metasilicate. We identify two distinct growth modes and show how continuous and discrete modulations in CO2 concentration, pH, and temperature can be used to deterministically switch between different regimes and create a bouquet of hierarchically assembled multiscale microstructures with unprecedented levels of complexity and precision. These results outline a nanotechnology strategy for "collaborating" with self-assembly processes in real time to build arbitrary tectonic architectures.

Media Coverage

Self-Assembled Micro-Structures by Wim Noorduin, Frame, March 8, 2015. 

Crystal nano flowers and the future of architectural chemistry, The Creators Project, June 2014. 

Complexity from simplicity, Science, May, 2013. 

Harvard researchers grow a garden of nanoscience flowers, Boston Globe, May, 2013. 

Gorgeous, intricate microflowers from mineral chemistry in a beaker, Chemistry & Engineering News, May, 2013. 

Tiny, delicate flowers grown in a beaker help to explain complex structures, Inside Science, May, 2014. 

Sculpting flowers smaller than a human hair, CNET, June , 2014. 

Nanogardens' sprout up on the surface of a penny, National Public Radio, May, 2013. 

Stunning microscopic 'flowers' created by chemical tweaking, WIRED Magazine, May, 2013. 

Nanoflowers grow in tiny garden, Discovery Channel, May, 2013. 

Gorgeous nanocrystal flowers sprout under electron microscope, Wired design, May, 2013. 

Microscopic crystal 'flowers' build themselves in a Harvard lab, NBC News, May, 2013. 

Des fleurs minérales microscopiques
Le Monde, May, 2013. 

These self-assembling nanoflowers are as beautiful as they are tiny, Popular Science, May, 2013. 

These aren’t flowers, Gizmodo, May, 2013. 

Spring has sprung in the lab, Daily Mail, May, 2013. 

Komplexe Strukturen: Blumenwiese aus dem Labor, Ingenieur, May, 2013. 

Microscopic flowers blooming in Harvard’s lab, ABC News, May, 2013. 

How to grow a nanogarden, Smithsonian, May, 2013. 

Tiny crystal flowers bloom in a beaker, CNET, May, 2013. 

Look: Harvard researchers grow a garden at nano-scale, Boston Business Journal, May, 2013. 

Condições ambientais conseguem modelar estruturas minerais, iG, May, 2013. 

Gärtnern in der Mikrowelt, Neue Zürcher Zeitung, May, 2013. 

A rosy start, National Geographic, May, 2013. 

Bloemen kweken op microschaal, NRC, May, 2013. 

Laat duizend kristallen groeien, De Volkskrant, May, 2013. 

Cómo construir un jardín de flores nanoscópicas, Redacción 1, May, 2013. 

Very fine art: 6 stunningly beautiful nanoscale sculptures, Scientific American, May 19, 2013. 

Des fleurs minérales cultivées dans l’eau, La Recherche, July, 2013. 

In the Nanogarden, New Scientist (US), June, 2013. 

Blühende Kristalle, Der Spiegel, 22, 2013. 

Rose in Nano, Spektrum der Wissenschaft, May, 2013. 

Il giardino dei nanofiori di cristallo, Focus (IT), June, 2013. 

En maiblomst av mineraler, Forskning och Framsteg, May, 2013.