The Seventy-six Standard Solutions, with Examples—Class 2

John Terninko,
Ellen Domb,
Joe Miller,


The “76 Standard Solutions” of TRIZ were compiled by G.S. Altshuller and his associates between 1975 and1985. They are grouped into 5 large categories as follows:


1.     Improving the system with no or little change                       13 standard solutions

2.     Improving the  system by changing the system                      23 standard solutions 

3.     System transitions                                                                 6 standard solutions

4.     Detection and measurement                                                17 standard solutions

5.     Strategies for simplification and improvement                       17 standard solutions

                                                                                    Total:  76 standard solutions


Class 1 of the 76 Standard Solutions and references to work by Altshuller and others appeared in the February issue of the TRIZ Journal, with a companion article on Su-field models, since many of the 76 are defined by the Su-field model of the situation.


This article covers Class 2, models that improve the system by changing the system.  There are examples from many fields of technology.  Readers are invited to send us their examples, for publication in future updates.  Class 3 will appear in the May, 2000 issue of the TRIZ Journal.


The example which are from Altshuller and his associates start with a bold GA.


Class 2. Developing the Substance-Field System


2 Transition to the Complex Su-Field Models.1.  Transition to the Complex Su-Field Models


2.1.1.  Chain Su-Field Model: Convert the single model to a chained model by having S2 with F1 applied to S3 which in turn applies F2 to S1.  The sequence of two models can be independently controlled.   Example: 

The hammer hits the rock.  The situation can be improved by placing a chisel between the hammer and rock. The mechanical field of the hammer is transferred to the chisel that then transfers the mechanical field to the rock.


S1 = rock

S2 = hammer

S3 = chisel

F1Me= impact force

F2Me = impact force


Figure G-10


The person holds the handle of the hammer and transfers muscle power to the handle.   The handle transmits the power to the head of the hammer.


2.1.2. Double Su-Field Model: A poorly controlled system needs to be improved but you may not change the elements of the existing system.  A second field can be applied to S2.   Example:

In the electrolytic process for creating copper sheet, small amounts of electrolyte are retained on the surface.  Washing is only partially effective in removing these deposits.  Adding a second field (mechanical agitation during washing, or washing in an ultrasonically vibrating bath) improves the cleaning action.


S1 = copper sheet

S2 = water

S3 = vibration generator

F1Me= pressure

F2Me = vibration



2.2. Forcing the Su-Field Models


2.2.1. Replace or add to the poorly controlled field with a more easily controlled field.  Going from a gravitational field to a mechanical field provides more control as does going from mechanical means to electrical or mechanical to magnetic.  This is one of the patterns of evolution of systems progressing from objects in physical contact to actions done by fields.  Examples:

Replace a hydraulic control system by an electrical or electronic system.

Replace a gravity flow control for intravenous solutions with an electrically controlled pump.  Improve it further by using feedback from a sensor in the patient’s bloodstream to control the delivery of medication.


2.2.2. Change S2 from a macro level to a micro level, i.e., instead of a rock consider particles.  This standard is actually the pattern of evolution from a macro- to micro-level. Examples:

Designing support systems to distribute a weight over irregular surfaces is

difficult.  A liquid filled bladder will distribute the load uniformly.

An automobile seat is being offered with several air bladders that are self-adjusting for all the body contact points.

Packing material (styrofoam “peanuts” or popcorn or other light, small particles) configures itself to fill the empty areas in a container.


2.2.3. Change S2 to a porous or capillary material that will allow gas or liquid to pass

through. Examples:

                Lubrication of gears with oil channels does not distribute the oil uniformly.  A

porous dispenser can be used.  Another version is a porous ball bearing.

Backpacking water purification systems use micropores to trap bacteria and let water pass through.

The evolution of ink writing systems has gone from a split nib functioning as a single capillary tube to a roller ball to a felt or fiber tip (multiple capillaries) to a porous ball.


2.2.4.  Make the system more flexible or adaptable; becoming more dynamic is another pattern of evolution.  The common transition is from a solid to a hinged system to continuous flexible systems.  Examples:

Either standard transmissions or automatic transmission in automobiles have a finite number of gear ratios.  A fluid system has an infinite number of gear ratios.

Mass customization, “flexible” factory that can produce any number of different configurations of a product. 

Reef points in a sail, so it can be used in a variety of wind conditions.  The next step is a roller reefing system, with continuous adjustment of sail area.

Self-shifting bicycle has weights on the spokes of the rear wheel.  The rpm is measured by the location of the weights, that is attached to the shift mechanism.  The further out the weight the higher the gear ratio.  The effect is constant rpm of the pedals.


2.2.5.  Change an uncontrolled field to a field with predetermined patterns that may be permanent or temporary.   Examples:

Standing waves are used to position liquids or particles.

Ultrasonic welding uses tuned devices (horns) concentrating vibrations to a small area.

Use polarized light to improve clarity of an image in a high-glare environment.


2.2.6. Change a uniform substance or uncontrolled substance to a non-uniform substance with a predetermined spatial structure that may be permanent or temporary.  Examples:

The problem is to create hollow large surface structure of minute particles to be heated to incandescence.  The famous ColmanTM lantern uses a mantel that becomes incandescent by burning white gasoline.  The mantel begins as a metal-impregnated fabric that is burned away.

The performance of concrete is improved by patterns of reinforcing rods.



2.3. Controlling the frequency to match or mismatch the natural frequency of one or both

elements to improve performance.


2.3.1. Matching or mismatching the frequency of F and S1 or S2.  Examples:

Vibratory feeders in manufacturing consist of a ramp fed by a reservoir of parts.  The system is tuned to the resonant frequency of the part to be transported up the ramp.

Kidney stones can be pulverized inside the body by exposing them to ultrasonic vibration at their resonant frequency.  (The process is called “lithotripsy.”)  The resulting small particles are then eliminated from the body painlessly.


S1 = stone

S2 = ultrasonic transducer

FMe= vibration




The resonant frequency of ultrasonic fixtures is at a non-harmonic frequency of the components being welded.

The precision of a rifle shot is improved by tuning the barrel oscillation to the bullet’s resonance by adjusting the position of a weight at the tip. 


2.3.2.  Matching the rhythms of F1 and F2Examples:

Fly fishing requires the back and forth frequency of motion of the pole to match the frequency of the line to reinforce the motion of the line.

Machine vibrations can be eliminated by generating the a new signal at the same amplitude but at a frequency 180 degrees out of phase.


2.3.3.  Two incompatible or independent actions can be accomplished by running each during the down time of the other.  Examples:

Placing and removing of a work item in a stamping press.

Timing for printing with injection printers.

Do maintenance on a building while the tenants are on vacation.  Note this example

pushes the boundaries of analogic thinking (vacation  and painting are substances) which

 is so important to using TRIZ.


S1 = painting

S2 = tenants

S3 = vacation

F1Me= access to space

F2Me = open space


2.4.  Integrating ferromagnetic material and magnetic fields is an effective way to improve the performance of a system.  In Su-field models, the magnetic field due to a ferromagnetic material is given the special designation Fe-field, or FFe.


2.4.1. Add ferromagnetic material and/or a magnetic field to the system. Examples:

Traveling magnetic field for propulsion on a railed vehicle.

Levitation of a monorail train.

See 1.2.2.


S1 = rail

S2 = train

S3 = Magnetic generator

S4 = Magnetic generator

F1M= lift

F2M = North pole

F3M = North pole


2.4.2. Combine 2.2.1 (going to more controlled fields) and 2.4.1 (using ferromagnetic materials and magnetic fields).  Examples:

The rigidity of a rubber mold can be controlled by adding ferromagnetic material and then applying magnetic field.

An atomic force microscope is used to deposit molecules (metal and semiconductor) on a gold surface, like ink on paper.


2.4.3. Use a magnetic liquid. Magnetic liquids are a special case of 2.4.2.  Magnetic liquids are colloidal ferromagnetic particles suspended in kerosene, silicone or water.

Ferrofluidic seals for doors, zero gravity applications, rotating shafts inside computer drives, etc.  (Ref. 8)

A magnetic door jam is used in conjunction with a door with a seal filled with ferrofluidic material with a given Curie point.  When the temperature is lowered below the Curie point the door is sealed. It can be opened by raising the temperature above the Curie temperature


2.4.4.  Use capillary structures that contain magnetic particles or liquid.  Example:

Construct a filter of ferromagnetic material between magnets. The alignment is controlled by the magnetic fields


2.4.5.  Use additives (such as a coating) to give a non-magnetic object magnetic properties.  May be temporary or permanent.  Example:

In order to direct molecules of medication to the exact location where they are needed in the body, attach a magnetic molecule to the drug molecule and use a external array of magnets around the patient to guide the medication where it is needed.


2.4.6. Introduce ferromagnetic materials into the environment, if it is not possible to make the object magnetic.  Example:

Place a rubberized mat with magnetic material encapsulated in it on a car to keep tools handy while working, without having to magnetize the car!  A similar device is used for surgical instruments.

S1 = tool

S2 = car

S3 = Magnetic material

F1Me= friction

F2M = Magnetic attraction



2.4.7. Use natural phenomena (such as alignment of objects with the field, or loss of ferromagnetism above the Curie point.) Examples:

Magnetic resonance imaging (called MRI in medicine and “nuclear magnetic resonance” or NMR in physics) uses a tuned oscillating magnetic field to detect the resonance of particular nuclei.  An image is then developed to show the concentration of those nuclei as colored areas.  For example, certain tumors have a different density of water than normal tissue, so they can be detected in an MRI scan as a different color from other tissue. 

See 1.2.5, 2.4.3

Superconductors change magnetic properties as they pass through the superconducting transition temperature.  Certain classes of superconductors can be  used as magnetic shields or switches to exclude magnetic fields from certain volumes of space as a function of temperature.


2.4.8. Use a dynamic, variable, or self-adjusting magnetic field.  Examples:

The thickness of the wall of an irregularly shaped hollow object can be measured using an inductive transducer on the outside, and a ferromagnet on the inside of the object.  To increase accuracy, make the ferromagnet in the shape of an inflatable elastic balloon coated with magnetic particles, so it will exactly fit the inside of the object being measured.

See 2.4.3.  The field will change as the fluid flows into different configurations.

To measure the motion of someone's diaphragm a magnetic material is place upon the outside of the diaphragm.  The motion of the magnetic material induces a current in a coil placed around the material.  Recording the current gives a read out of the diaphragm motion. 


2.4.9. Modify the structure of a material by introducing ferromagnetic particles, then apply a magnetic field to move the particles. More generally, the transition from an unstructured system to a structured one, or vice versa, depending on the situation. Examples:

The conductivity of a polymer can be improved by doping with conductive material.  If the material is ferromagnetic then a magnetic field can align the material, to a more effective conductor requiring less doping.

To form a complex pattern on the surface of a plastic mat, mix ferromagnetic particles into the liquid plastic, then use a structured magnetic field to drag the particles into the desired pattern and hold them there while the mat is solidified.

S1= plastic

S2= mold

S3 = magnet material

S4 = magnet

F1Me = barrier

F2M = magnetic force

2.4.10.  Matching the rhythms in the Fe-field models. In macro-systems, this is the use of mechanical vibration to enhance the motion of ferromagnetic particles.  At the molecular and atomic levels, material composition can be identified by the spectrum of the resonance frequency of electrons in response to changing frequencies of a magnetic field.  Examples:

Material composition can be identified by the spectrum of the resonance frequency of electrons in response to changing frequencies of a magnetic field.  Each atomic family has a signature of resonant frequencies. The technique is called ESR, Electron-Spin Resonance

Microwave ovens heat food because they cause the water molecules to vibrate at their resonant frequency.


2.4.11. Use electric current to create magnetic fields, instead of using magnetic particles.  Examples:

Electromagnets of all shapes and sizes.   They can be used in temperature ranges beyond the Curie point of magnetic materials, and in areas where permanent magnets cannot be secured.  They can have the further advantages that they can be turned off when not in use, and they can be finely tuned to an exact magnetic field by varying the current.


2.4.12.  Rheological liquids have viscosity controlled by an electric field.  They can be used in combination with any of the methods here.  They can mimic liquid/solid phase transitions. Examples:

A “universal chuck” secures any shape part to a milling machine.   The part is placed in a pool of rheological liquid, positioned properly, then an electric field is applied to solidify the liquid and secure the part.

In a dynamic shock absorber, the system is controlled using an electric field to allow or inhibit the flow of a rheological liquid.


Note of Gratitude:
Our thanks go to Zinovy Royzen for sharing his method of Su-field modeling called TOP modeling.  See  “Tool, Object, Product (TOP) Function Analysis” in the September, 1999, issue of The TRIZ Journal,