Fine Measurement Machines

Example of relationships between

science and technology/engineering

The Purpose of Science and Technology/Engineering Education

Massachusetts Science and Technology/Engineering Framework

Investigations in science and technology/engineering involve a range of skills, habits of mind, and subject matter knowledge. The purpose of science and technology/engineering education in Massachusetts is to enable students to draw on these skills and habits, as well as on their subject matter knowledge, in order to participate productively in the intellectual and civic life of American society and to provide the foundation for their further education in these areas if they seek it.

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The Relationship Between Science and Technology/Engineering

Massachusetts Science and Technology/Engineering Framework In spite of their different goals, science and

technology have become closely, even inextricably, related in many fields. The instruments that scientists use, such as the microscope, balance, and chronometer, result from the application of technology/engineering. Scientific ideas, such as the laws of motion, the relationship between electricity and magnetism, the atomic model, and the model of DNA, have contributed to achievements in technology and engineering, such as improvement of the internal combustion engine, power transformers, nuclear power, and human gene therapy. The boundaries between science and technology/engineering blur together to extend knowledge.

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Atomic Force Microscopes (AFMs) are used Atomic Force Microscopes (AFMs) are used to make nanoscale measurementsto make nanoscale measurements

http://en.wikipedia.org/wiki/File:Atomic_force_microscope_by_Zureks.jpg

An AFM generated this image of the An AFM generated this image of the ionic crystal lattice array of sodium chloride.ionic crystal lattice array of sodium chloride.

http://en.wikipedia.org/wiki/Image:AFM_view_of_sodium_chloride.gif

This example of a schematic drawing reveals This example of a schematic drawing reveals some essential components of an AFM.some essential components of an AFM.

http://en.wikipedia.org/wiki/Image:Atomic_force_microscope_block_diagram.png

Key features of an AFM include:Key features of an AFM include:

A flexible cantilever that exerts a small amount of A flexible cantilever that exerts a small amount of downward force on an object so that the object is not downward force on an object so that the object is not damageddamaged..

A mirror that creates a long pathway for reflected light to A mirror that creates a long pathway for reflected light to travel so that the motion of the tip at the and of the travel so that the motion of the tip at the and of the cantilever is multiplied.cantilever is multiplied.

.

Analysis: Distance Multiplier

cantilever

laser

Long light path and a short cantilever gives large amplification

d1

d2

L1

L2

pivotpoint

The distance amplification d2/ d1 is proportional to L2/ L1

The goal of today’s activity is to provide The goal of today’s activity is to provide students an opportunity to:students an opportunity to:

• Assemble a device that can be used to measure the thinness of an object.

• Calibrate that device.• Improve the sensitivity of the device.• Determine how much the device multiplies

motion.• Develop a strategy to map an uneven surface.• Construct a diagram that represents changes in

the thinness of an object.

A lever can also make fine measurements.A lever can also make fine measurements.

The mirror at one end of the lever creates a long pathway The mirror at one end of the lever creates a long pathway for reflected light to travel. for reflected light to travel.

Laser PointerRuler

Lever supportmirror

Hanging mass

If a thin object moves under one end of the lever arm, it If a thin object moves under one end of the lever arm, it causes the lever arm to move a short distance and the causes the lever arm to move a short distance and the point of light on the ruler moves a greater distance. point of light on the ruler moves a greater distance.

The reflected light beam now reaches a different point on the ruler.

A hanging mass can be placed in a position on the short A hanging mass can be placed in a position on the short arm of the lever so that the long lever arm does not exert a arm of the lever so that the long lever arm does not exert a

lot of downward force on the object that is being measuredlot of downward force on the object that is being measured..

The lever needs to be able to respond to subtle changes in thinness.

An object of a known thinness can be used to An object of a known thinness can be used to calibrate the measurement machine.calibrate the measurement machine.

The calibration reveals the relationship between the movement of the lever and the movement of the point of light on the ruler.

There will be a number of tasks There will be a number of tasks for team members to share.for team members to share.

• Establishing a work area.• Coordinating your group’s movements with

other groups.• Assembling the machine.• Managing the experimental procedure.• Working with the laser pointer carefully.• Collecting and recording data.• Keeping the lever assembly stable.

Some important questions Some important questions

How was your measurement machine similar to How was your measurement machine similar to the design of an Atomic Force Microscope?the design of an Atomic Force Microscope?

How was your measurement machine different How was your measurement machine different from the design of an AFM?from the design of an AFM?

How can this activity effectively be integrated How can this activity effectively be integrated into the STEM curriculum?into the STEM curriculum?