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11. Living machines

John Todd and Nancy Jack Todd

This chapter continues our exploration of technologies that incorporate the ecological wisdom of nature. It introduces our readers to what we consider today's most advanced and most revolutionary technologies of this kind. The authors have been on the forefront of these revolutionary developments for the past twenty-five years. John Todd, visionary biologist and ecological designer, is the founder of the now-legendary New Alchemy Institute and the Center of Restoration of Waters at Ocean Arks international in Massachusetts, where he has pioneered "living technologies," and in particular the "living machines" described in the following pages.

Nancy Jack Todd has been active in the environmental movement for over two decades. As cofounder of the New Alchemy Institute, editor of its journals, vice president of Ocean Arks, and editor of their publication, Annals of Earth, she has been the primary force behind communicating their results to n worldwide readership. Both authors have published numerous articles and several books on ecological design, including most recently the jointly authored volume, From Eco-Cities to Living Machines: Principles of Ecological Design (1994).

This chapter is an inspiring introduction to a novel and wonderful branch of ecological design. As the authors explain, a living machine is a contained ecosystem comprising hundreds, even thousands, of species of carefully selected organisms. It is a machine, because it has been designed and built to perform specific tasks. At the same time, however, it is fundamentally different from conventional machines and even from standard biotechnologies.

The design of these new, human-created ecosystems not only in corporates all the principles of ecology, but also uses the inherent intelligence of the ecological community contained in the structure. Like natural ecosystems, living machines are capable of repairing themselves, replacing their components as they wear out, and of responding creatively to change by "evolutionary" self-design.

Living machines have been designed and built to produce food, heat and cool buildings, treat wastes, and purify the air. Most astonishingly, they can perform all of these functions simultaneously. Prototypes of these miracles of ecological design are now being installed throughout the United States, and in Canada, the United Kingdom, and Australia. The authors estimate that eventually, these living technologies will be up to 10,000 times more effective than conventional technologies. In terms of energy and chemical inputs, the existing examples are already ten to one hundred times more effective.

We have included a few photographs of living machines with the chapter, because we feel that their strong aesthetic appeal will prove as important to their success as the fascinating theory behind them and their amazing economic performance. Being machines, gardens, and works of art all rolled into one, living machines are major milestones on the road toward sustainability.

The innumerable and life-endangering environmental ills that currently plague us globally and locally are the byproducts of human cultures and technologies deeply estranged from the great natural systems of the planet. These same systems are, ironically, the very processes that ultimately sustain us. Edward Wilson has calculated that humans are destroying species at an extraordinary rate and that between twenty and fifty percent of present living species will be extinct by the year 2025. The only lasting solution to counter this dynamic is to recreate consciously symbiotic relationships between humanity and nature. Such relationships demand nothing less than a fundamental technological revolution designed to integrate advanced societies with the natural world.

Such a revolution is well underway. We have been involved in applied research into truly sustainable and equitable means for supporting the peoples of the world for more than twenty five years. Among the most encouraging recent developments has been the invention of living technologies that literally harness the intelligence, processes, and organisms found in nature not only to support human society but to restore damaged and polluted ecosystems. The component units of living technologies, called living machines, can be designed to produce food or fuels, to treat wastes, to purify air, to regulate climate, and to bioremediate ravaged ecosystems. Furthermore, they can do all of these simultaneously.

A living machine is a contained ecosystem made up of thousands of species of selected living organisms. Such an ecosystem is usually housed in a casing or structure, frequently a series of cylinders, made up of light-weight and sometimes light-transmitting materials. It is similar to a conventional machine in that it is comprised of a number of interrelated parts that function together to perform an assigned task. The design is based on principles evolved over millennia by the natural world in regulating the great ecologies of forests, lakes, prairies, and estuaries, and the ecosystems within ecosystems that are their component parts. Their primary energy source is sunlight. Mirroring the metabolism of the planet, living machines are driven by hydrological, mineral, and climate cycles.

It must be emphasized that while drawing on the ancient intelligence of nature, living machines are entirely new, humanly created ecosystems. In order to build a living machine, organisms from a vast range of sources are collected and reassembled in any number of combinations, some of which can prove unique. In the novel setting of the interior of the living machine, these organisms develop into populations co-existing often in unprecedented combinations or communities that quickly adapt to a given assignment. Depending on the goal of the project, the parts or living components may come from almost any region of the planet and be recombined in a rich variety of ways. Appropriate assembling is based on knowledge of the niches and the natural history of the organisms that are to make up the constituent parts, and on calculation of their individual role amid the constellation of organisms being incorporated by the designer.

Ultimately. it should be possible to design living machines that are at least four orders of magnitude more effective than conventional technologies. In terms of energy and external chemical inputs, our recently developed waste treatment technologies are already two to three orders of magnitude more effective than existing, conventional methods.

Much of the early research in living technologies was undertaken to reverse and transform the alarming and worsening state of the world's waters. All over the earth, we have poured into formerly pristine waters such toxins as fertilizer runoff and industrial, chemical, and human wastes. Countless species of fish, molluscs, frogs, and amphibians generally are or are becoming extinct. Nor are these the only species at risk. In spewing thousands of chemicals into the environment, we find many of them returning to us via the water in food chains to become embedded in the cells of our bodies and those of our children. The challenge is to develop modern support systems with the ability to rapidly reverse this trend.

Because water is fundamental to all living systems, the starting point is the transformation of water-based technologies. As a substance, water is something of a scientific freak, having the rare property of becoming denser as a liquid than it is as a solid. This property is one of the reasons life is possible here on Earth. If, like other chemical substances, the solid state were denser, lakes would freeze, from the bottom up, into great blocks of ice that would never melt. The whole planet would be a lifeless ball of ice. The waters of the Earth maintain in balance all of the chemical elements of the planet and all its gases. Water is the major regulator of climate. All land-bound life evolved from this life-giving source. Approximately seventy per cent of the human body is comprised of water. If, as the Russian biologist Vernadsky claimed, water is life, the quality of water in many ways determines the quality of life.4 Now, however, water is becoming the source, not of life, but of illness, debilitation, carcinoma, and death.

There is, however, a way of reversing this seemingly irrevocable dynamic. Living machines, by adopting and mimicking the strategies of natural systems, have proved extraordinarily effective in detoxifying and restoring the most severely contaminated waters.5 Based on the premise that waste is a resource out of place and that nature handles every form of waste by turning it into a resource, living machines imitate the purifying and recycling abilities of natural aquatic ecosystems. Powered by sunlight and frequently housed in greenhouse-like structures, they contain populations of bacteria, algae, microscopic animals, snails, fish, flowers, higher plants, and trees. Such living machines have proved capable of advanced water treatment without resorting to the hazardous chemicals used in most existing treatment plants at competitive costs in today's terms.

We have designed and built living machines to grow food, to heat and cool buildings, to bioremediate naturally occurring bodies of water and to treat sewage, sludge, septage, and boat wastes.6 It is possible to apply the same kind of biological engineering to the production of high-quality biogas fuels. Living machines produce byproducts that can be used in the manufacture of materials ranging from paper products to advanced composite construction materials. They can be linked together to form an engineered ecology, a living technology that can be designed to protect and restore natural environments and to support human communities.

A Comparison of Living Machines with Conventional Technologies

  Living Machines Conventional Technologies
Primary Sources The Sun Fossil fuels, nuclear power
Secondary Sources Radiant energy Internal biogenesis of gases
    Combustion and electricity
Control Electricity, wind, and solar electric Electrical, chemical, and mechanical
Capture of External Energy Intrinsic to design Rare
Internal Storage Heat, nutrients, gases Batteries
Efficiency Low biological transfer efficiency in subsystems, high overall aggregate efficiency High in best technologies, low, when total infrastructure is calculated
Flexibility Inflexible with regards to sun- light, flexible with adjunct energy sources Inflexible
Pulses Tolerant and adapted Usually intolerant, tolerant in specific instances
Design Parts are living population Hardware-based
  Structurally simple Structurally complex
  Complex living circuit Circuit complexity often reduced
  Passive, few moving parts Multiple moving parts
  Dependent entirely upon environmental energy and internal storage systems Energy-intensive
  Long life spans.. centuries Short life spans... decades
  Materials replacement Total replacement
  Internal recycling intrinsic Recycling usually not present
    Pollution control devices used
  Living Machines Conventional Technologies
  Ecology is scientific basis for design Genetics is scientific basis for biotechnology
    Chemistry is basis for process engineering
    Physics for mechanical engineering
Materials Transparent climatic envelopes Steel and concrete
  Flexible lightweight containment materials Reliance on motors
  Electrical and wind-powered air compressors/pumps Structurally massive
Biotic Design Photosynthetically based ecosystem Independent of sunlight
  Linked sub-ecosystems Unconnected to other life forms
  Components are living populations Only biotechnologies use biotic design
  Self design No self design
  Multiple seedings to establish  
  Internal structures  
  Pulse driven  
  Directed food chains: end points are products including fuels, food, waste purification, living materials, climate regulation  
Control Primarily internal throughout complex living circuits Electrical, chemical, and mechanical controls applied to system
  Threshhold number of organisms for sustained control External orchestration and internal regulation
  All phylogenetic levels from bacteria to vertebrates act as control mechanisms  
  Disease is controlled internally through competition, predation, and antibiotic production Through application of medicines
  Feedstock both internal and external Feedstocks external
  Modest use of electrical and gaseous control inputs orchestrated with environmental sensors and computer controls Sophisticated control engineering
Pollution Pollution, if occurs, is an indication of incomplete design Pollution intrinsically a by product; capture technologies need to be added
  Positive environmental impact Negative or neutral environmental impact
Management and Repair Training in biology and chemistry essential Specialists needed to maintain systems
  Empathy with systems may be a critical factor Empathy less essential
Costs Capital costs competitive with conventional systems The standard
  Fuel and energy costs low Fuel and energy costs high
  Labor costs probably analogous
- still to be determined
The standard
  Lower pollution control cost The standard
  Operation costs lower because of reduced chemical and energy input The standard
  Potential reduction of social costs, in part because of potential transferability to less industrialized regions and countries Social costs can be high

Living machines are fundamentally different from both conventional machines and standard biotechnologies. They represent, in essence, the inherent intelligence of a forest or a lake being applied to human ends through tasks that serve human societies. Like natural ecosystems, they engage in a process of self-design. They rely on biotic diversity for self-repair, protection, and overall system efficiency. It is their aggregate characteristic that most distinguishes living technologies, however. People accustomed to the mechanical moving parts, the noise or exhaust of internal combustion engines, or the silent geometry of electronic devices often have difficulty imagining living machines. Complex life forms viewed inside light-receptive structures can seem at once familiar and bizarre. They are both garden and machine, alive yet contained and framed living technologies that bring people and nature together in radical and transformative new relationships.

Much of the potential of living machines to protect and enhance neighboring environments lies in their photosynthetic base. Although secondary sources of energy can be and are used for control and light augmentation, both the unique adaptiveness and economic viability of living technologies lie in their dependence on photosynthetically-based food chains. They are built with parts that are themselves living populations, often extremely diverse, comprised of hundreds of species. A primary and key attribute is that the components will replace themselves as they wear out. The life span of some populations can be extraordinary, as long as centuries if housed in suitably durable containers. Further, such systems have abilities to respond and change with variations in inputs. They have the ability to self-design. Although the task is established by the human designer, when the living machine is left to express its own complexity, it may develop biotic relationships unknown in nature, thereby expanding its options for diversity. An interesting example of self design occurred recently in a living machine treating high-strength food wastes in a desert environment when the computing controls regulating flows to the system were knocked out. As a consequence, the volume of waste entering the system exceeded the design capacity of the living machine by a factor of ten for several days. The treatment facility was overwhelmed with fats, oils, and grease. Many of the organisms, including fish, were killed. The problem was discovered on a Friday afternoon and the influent pumps were stopped. Returning on the following Monday morning the plant engineers were surprised to discover that the system had self-repaired or healed itself, digested the mess of wastes, and was ready to start in again treating new material. This was possible because refugia or small side-streams had been designed into the system. These provided habitats where organisms could survive extreme conditions then re-invade and rapidly repopulate the affected zones of the living machine. This process can occur with surprising speed. We have observed a number of examples of this dynamic aspect of ecologically engineered systems.

An important aspect of living technologies, like natural systems in the wild, is that they are pulse-driven. Daily, seasonal, and sporadic variations stamp themselves deeply on their internal ecology. The background of pulses creates the resilience, agility, and vigor necessary for the systems to recover from external shocks, a response impossible for conventional machines. Yet another essential attribute is the presence of control species within the contained ecosystems. These species orchestrate the overall ecology. The building blocks behind the design, however, are the life histories of the organisms. It is essential to graft the evolution of living technologies onto a foundation of wide-ranging knowledge of natural history. The world is a vast repository of as yet unknown biological strategies that could have immense relevance should we develop the science of integrating the stories embedded in nature into the systems we design to sustain societies. Conservationists and preservationists rightly honor nature and struggle to protect the pristine natural areas that remain to us. The survival of civilization equally may require another fundamental step. It may be essential for us to find ways of decoding the natural world and of using its teachings to reshape and redefine our tools and technologies. Good farmers and gardeners have long had this kind of relationship with nature. With the unfolding and application of ecology it is possible to extend this relationship into new dimensions.

The development of living technologies had to await not only the advent of ecology as a discipline and source of knowledge but also the advancement of materials sciences to the point at which energy-efficient and environmentally responsive materials could be manufactured cost-effectively. The containment vessels frequently use light-weight, light-transmitting flexible materials that can be bonded and waterproofed, or that be floated on top of aquatic ecosystems.

Economically and energetically, living machines make enormous sense. They are cost-competitive in many areas of food growing and in purifying concentrated wastes. By avoiding any use of hazardous chemicals, they can be designed to be pollution-free in operation. It is anticipated that the aesthetics of living technologies, in addition to their functional and economic soundness, will hasten their acceptance. They can be designed to be beautiful and evocative of the deep harmonies found in nature. New economies that are an outgrowth of the wisdom and resilience of the natural world would create a new and hopeful dimension for the future.

Living machines need not be small nor isolated from larger natural systems. Scale is not an overriding factor as living technologies, like the natural world, are made up of parts that are cellular in design. Each subcomponent shares the universal attributes of organisms, namely of autonomous components fused ingeniously into interdependent associations that comprise the self-regulating whole. These include such independent attributes of life as self-repair, replication, feeding, and waste excretion dynamically balanced with interdependent functions like gas, mineral, and nutrient exchange. The same natural design principles that extend from the cell to encompass all planetary biota allow living machines to vary greatly in size. They have been designed for classroom use to exhibit the functioning of ecosystems, and for treating household wastes in containers comparable to appliances like an average washing machine and dryer. So far the largest that we have designed encompasses an area of seven hectares. Conceptual projects include living machines for providing ultra-high-quality drinking water for the city of Boston that would extend for 100 kilometers inside a greenhouse-covered canal.

Looking to the 21st century, the potential contribution of living technologies is incalculable. Although fossil fuels are necessary to manufacture the long-lived materials of which the containers and mechanical parts are made, they are not needed for ongoing use. Living machines are capable of reintegrating wastes into larger systems and of breaking down toxic materials or, in the case of metals, recycling them or locking them up in centuries-long cycles. Living machines make it possible to produce large amounts of food in urban or remote areas and, as a result, could be part of a strategy for addressing issues of inequity between peoples and regions. Some less fertile parts of the world, like the semi-arid subtropics, would benefit enormously as the tropics are the greatest reservoirs for the necessary spare parts. By miniaturizing the production of essential human services living technologies have the further potential of releasing natural systems from human abuse. This would free nature to continue to evolve in a wild state, free from excessive human interference, greatly reducing the human footprint on the ecology of the planet. This is relevant in that the long-term survival of humanity may well be predicated on a dramatic increase in the wilderness areas that are the great repositories of the Earth's biological diversity and evolutionary heritage.

The barriers to the transition from an industrially based economy to a postindustrial ecological economy are not as great as is generally assumed. Living-machine technologies for food production pioneered by the New Alchemy Institute in the 1970s are now widely employed in commercial food production and some are multimillion dollar enterprises.7 Waste treatment technologies are evolving rapidly and are already cost effective in many settings. When current environmental, medical, and social costs are computed they are already adaptive in a range of settings including tropical areas. Environmental repair technologies for the restoration of lakes and polluted waters are now more cost effective than alternatives.8 An additional and relevant attribute of living machines is that they also can be added onto existing technologies to upgrade performance and reduce pollution. In 1994 we installed a living machine at the outfall of a secondary sewage treatment plant in San Francisco. Its function is to upgrade the quality of the water being discharged so that it can be resold and reused rather than dumped into the ocean.

Living machines also can be designed to reduce or eliminate hazardous emissions from industrial manufacturing facilities. They can readily be integrated into the infrastructures of contemporary societies. Their potential to transform the visual landscape of the industrial world has been portrayed in drawings by the architect and visionary, Malcolm Wells.9

Ecological technologies have the ability to transform the way we live and sustain ourselves. The challenge lies in a dramatic rethinking of the human enterprise in order to redesign it to fit the laws and the needs of the natural world. Paul Hawken in The Ecology of Commerce states the issue clearly: "To create an enduring society, we will need a system of commerce and production where each and every act is inherently sustainable and restorative. Business will need to integrate economic, biologic and human systems to create a sustainable method of commerce." He then goes on to say quite appropriately: "As hard as we may try to become sustainable on a company-by-company level, we cannot fully succeed until the institutions surrounding commerce are redesigned.''10 Ecology provides the foundation and living technologies the infrastructure for such redesign.


1 Wilson, E.O. 1992. The Diversity of Life. W.W. Norton, New York.

2 Todd, J. & B. Josephson. 1994. "Living Machines: Theoretical Foundations & Design Precepts." Annals of Earth, Vol. 12, No. 1, pp. 16-24.

3 This is best represented by the new living machine for sewage treatment de signed by Ocean Arks International and engineered by Living Technologies Inc. at Frederick, Maryland. It is a U.S. Environmental Protection Agency facility for the demonstration of ecologically engineered technologies.

4 Lapo, A. 1987. Traces of Bygone Biospheres. Synergetic Press, London. (Translated from the Russian.)

5 Todd, J. 1992. Chattanooga Creek Pilot Remediation Project: Report to the U.S. Environmental Protection Agency. Ocean Arks International, Falmouth, Massachusetts. (28 pp.)

6 Todd, N.J. & J. Todd. 1994. From Eco-Cities to Living Machines: Principles of Ecological Design. North Atlantic Books, Berkeley, California.

7 Todd, J. & N.J. Todd. 1980. Tomorrow is Our Permanent Address: The Search for an Ecological Science of Design. Harper and Row, New York.

8 Todd, J. 1994. The Flax Pond Restoration Project: 1994 Annual Report to the Town of Harwich. Ocean Arks International, Falmouth, Massachusetts. (125 pp.)

9 Wells, M. 1994. Infra Structures: Life Support for the Nation's Circulatory Systems. Underground Art Gallery, Brewster, Massachusetts.

10 Hawken, Paul. 1993. The Ecology of Commerce. Harper Business, New York.

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