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. Page 8:

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. Page 8:

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

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

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

Key features of an AFM include: A flexible cantilever that exerts a small amount of downward force on an object so that the object is not damaged. A mirror that creates a long pathway for reflected light to travel so that the motion of the tip at the and of the cantilever is multiplied. Key features of an AFM include: A flexible cantilever that exerts a small amount of downward force on an object so that the object is not damaged. A mirror that creates a long pathway for reflected light to travel so that the motion of the tip at the and of the cantilever is multiplied.

. Analysis: Distance Multiplier cantilever laser Long light path and a short cantilever gives large amplification d1d1 d2d2 L1L1 L2L2 pivot point The distance amplification d 2 / d 1 is proportional to L 2 / L 1

The goal of todays activity is to provide 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. The mirror at one end of the lever creates a long pathway for reflected light to travel. A lever can also make fine measurements. The mirror at one end of the lever creates a long pathway for reflected light to travel. Laser Pointer Ruler Lever support mirror Hanging mass

If a thin object moves under one end of the lever arm, it causes the lever arm to move a short distance and the point of light on the ruler moves a greater distance. If a thin object moves under one end of the lever arm, it causes the lever arm to move a short distance and the 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 arm of the lever so that the long lever arm does not exert a lot 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 calibrate the measurement machine. An object of a known thinness can be used to 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 for team members to share. Establishing a work area. Coordinating your groups 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 How was your measurement machine similar to the design of an Atomic Force Microscope? How was your measurement machine different from the design of an AFM? How can this activity effectively be integrated into the STEM curriculum? Some important questions How was your measurement machine similar to the design of an Atomic Force Microscope? How was your measurement machine different from the design of an AFM? How can this activity effectively be integrated into the STEM curriculum?