Natural Process Design Inc.

Self-Repairing Matricies


Designing with Natural Processes

(building as if you are part of nature)

summary of self repair technology in concrete

By Carolyn Dry, Ph.D.

summary of self repair technology in polymer composites  


We have developed several materials/technologies that address the issue of how to build with the natural processes of nature and concurrently take up some of the effluents of our fossil fuel/CFC economy and prepare for a new non fossil fuel/CFC economy.
Nature builds with 1) cheap often recycled materials, 2) that can self repair, 3) self sense, 4) return to the sink of materials by recycling and, 5) often improve the environment and 6) self form. Examples of each topic and materials developed are:

Fly ash is the product of burning coal and contains many heavy metals and is largely carbon. We have developed a way of making it into building panels of nearly all ash so that these metals are sequestered and do not leach out to pollute the environment.

      Figure 1) Left are the fly ash spheres and right is one of my fabricated panels

2a) The making of cement produces 10% of the world’s CO2. I developed a self repairing cement/concrete so that less cement would need to be replaced. We made four full size bridges of this.

2b) Also, our polymer composites made of graphite from oil are self repairing. It is expected that airplane composite portion of the fuselage could be 30% lighter which would greatly save fuel use and CO2 emissions. (an airplane trip uses three times the gas for a car trip of the same distance) We did this work for the U.S. Air Force.

Figure 2) Left is self repairing concrete bridges and right is self repairing airplane wing


These self repairing materials can be self sensing of the state of damage and repair. Further, these self repairing and self sensing materials could help materials survive longer and thus reduce the use of oil. We made self repairing and sensing components for airplanes such as wings which we are now commercializing.

Figure 3) Left is sensing system and right is the damages or bruised composite with red repair/sensing material showing as damaged areas

Concrete girders have embedded in them high tension metal rods that can break and blow the whole girder and surrounding structures apart when cut, so we developed a way of dismantling them so they can be taken out and the rest of the bridge remain intact.

Figure 4) a photo of the girders being fabricated 

Much of the greenhouse gases, especially CO2, released during calcining of cement can be taken up by the concrete over time. I developed a paint that utilizes this ability and speeds it up. It can be used on highways or buildings. It takes up CO2 in roads at the source, automobile tailpipes, and the reaction strengthens and repairs the concrete and extends its lifetime while improving the environment by taking up greenhouse gases and CO2.


Figure 5) Left are the bridges with CO2 sequestering coatings and right is a slice of the concrete showing how far the CO2 penetrated.

Nature self forms materials by a process involving the uniting of a property of the environment with a property of the material. In the first project, I united all of these aspects into one system.  Based on a technology developed by another researcher, Wolf Hilbertz, I worked on a self forming system that uses the chemistry of seawater to make a port. That project was a good example of self forming. The electrolytic sea water can carry an electrical charge and move calcium ions onto the charged structure. This forms a coral or bone like material.
The part I did is based on the fact that we evolved from seawater: our lymph is exactly like seawater in chemical composition, so I looked to the human body for inspiration. This bone like structure in the ocean, then like bone, repairs itself by more stress which pulls out more calcium from the ocean and like your nerves it can sense using charged ions going over a membrane and can move parts like our muscles do by using different chemical concentrations in water.



Figure 6) Top is a drawing of the ocean port which performs all functions by using the chemistry of seawater, lower left shows how the port structure repairs under bending, like bone, using electrical charges, right is a bone.

Following the bone analogy I also developed a cement and polymer material that forms like bone in which the polymer forms a template for the cement to follow.
It has the advantages of the hard cement which is strong and of the plastic which can bend.


Figure 7) A microscope photo of the cement/polymer material
Some of my recent work is to look beyond a fossil fuel/CFC economy.  These ideas are

  1. projects in self repairing hydrogen tanks, and wind mill wings
  2. coatings and materials that take up all manner of gases
  3. integrated appliances including energy production and refrigeration; an energy efficient window
  4. two unique car propulsion systems, one airplane propulsion system,  
  5. pleaching trees for living structures.

The earth was formed in the same event with Mars, Venus, and the other planets from the big bang. So they were very similar in composition but not size. Currently Venus is very hot and Mars is cold and in one day they have a wide temperature cycle. The earth has evolved differently to have a stable, moderate temperature in a small range with a breathable atmosphere, it can support animal life. How did this happen?  Our atmosphere of gases from the center of the earth, emitted from volcanoes, was toxic, full of methane, sulfur and CO2. It was incredibly hot with very large heat fluctuations. But, gravity held in the atmosphere and eventually plant life was formed from bacteria and transformed the atmosphere from such a reducing one to an oxygenated one that animals could breathe. This atmosphere insulated the earth and stabilized the climate to a small range of steady temperatures that were cool and warm enough to support animal life.  Now, we are driving that evolution of the atmosphere backwards with too much reducing gas as CO2 and against our own survival as animals. Also, an ozone layer formed which protects against ultraviolet radiation and a large hole is developing which threatens the phytoplankton which produce some 60% of the worlds oxygen we breathe. It is thought to be even more serious than the buildup of greenhouse gases.
The most effective solution to the problem of too much CO2 is to plant more trees, stop cutting them down, and stop burning old plants (fossil fuels) which produces so much CO2 and take up the effluents of this fossil fuel and CFC ozone depleting economy.


All Material Copyright 2005 Carolyn Dry and Natural Process Design Inc..................