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					Big idea: Tools & Instrumentation
Development of new tools and instruments helps drive scientific progress. Recent
development of specialized tools has led to new levels of understanding of matter by
helping scientists detect, manipulate, isolate, measure, fabricate, and investigate
nanoscale matter with unprecedented precision and accuracy.

Clarification-

       Technology plays an important role in scientific progress, as science and

technology often drive one another. The degree to which we understand the world is

limited, in part, by the tools available to investigate it. The tools and instruments

available to scientists determine what is accessible for them to measure. This

accessibility leads scientists to new understandings and new questions, which is part of

the scientific process. Thus, development of tools plays an important part in the

progress of science. Telescopes, for example, allow for the exploration of distant

portions of the universe, while optical microscopes enable the investigation of a world

that is otherwise too small to see. The development of each of these tools led to

enormous gains toward understanding the systems within these worlds. Likewise,

scientific hypotheses and theories create a need for new tools and instruments. For

instance, Galileo used a telescope to examine the heavens and proved Copernicus’

theory about a heliocentric solar system.

       The recent development of tools and instruments (e.g. scanning probe

microscopes) has rendered the nanoscale world accessible in ways impossible to fathom

just a short time ago. These new instruments allow scientists to characterize nanoscale

materials and objects with relative ease. This new accessibility has lead to new
understandings of matter on this scale and has aided in the development of new

applications.

Why is this a ‘big idea’?

       Throughout history, the development of new instruments has provided access to

previously unseen worlds. Galileo created the telescope and revealed that the Earth is

part of a complex planetary system. Today, a variety of telescopes orbit the Earth

examining the heavens using not just visible light, but light from the entire electro-

magnetic spectrum. The information they gather is providing insight into the formation

of the solar system and the Universe itself. Development of new technology has sent

probes to distant planets and has even enabled humans to travel through space and

explore it themselves.

       The field of microscopy has allowed scientists to visualize and explore worlds

too small to be seen. In the 17th century, Anton van Leeuwenhoek’s optical microscope

opened the world of small biological organisms. He discovered that a drop of water

was teeming with life and observed that blood was corpuscular in nature. This was the

beginning of the biological revolution and lead to a deeper understanding of the

structure and function of living organisms. However, the size of objects that optical

microscope can visualize is limited to one half the wavelength of the light used for

detection. This puts the resolution limit at ~ 0.2 µm when using visible light.

       The latter part of the twentieth century saw tremendous advances in microscopy.

The scanning electron microscope (SEM) uses a focused beam of electrons to scan a

sample and create and image. This technology allows objects on the scale of less than 10
nm to be resolved and has played an important role in the development of nanoscale

science and engineering. Scanning probe microscopes are another set of tools for

investigating the nanoscale world. Similar to the SEM, this class of tools also creates

images by scanning the sample surface (scanning probe microscopes, (SPMs)), but with

a physical probe instead of a beam of electrons. The type of probe determines the type

of information that can be obtained. For example, an atomic force microscope (AFM)

uses a metal probe that tapers down to a point that has a radius of less than 10 nm. This

probe scans the surface of the sample, detecting the interatomic and intermolecular

forces between the probe and the surface to create the image. This process is much like

using a finger to read Braille. An AFM can measure surfaces with atomic resolution.

Other probes can be used to measure other properties of a sample when appropriate,

including the size and strength of magnetic features, how well the material conducts

heat and the optical properties of a surface. While there are many techniques and

instruments that allow scientists to probe nanoscale matter, the type of samples for

which these microscopes are optimal and the ease with which they visualize the

nanoscale, is a driving force behind the nanotechnology revolution.

       Like any instrument, these microscopes have limitations on the type of sample.

Because of the nature of biological materials, these tools are not amenable to measuring

certain types of information about biological systems. Instead, researchers use a variety

of spectroscopic techniques to directly and indirectly probe the structure and function

of biological molecules and systems. X-ray crystallography and nuclear magnetic
resonance spectroscopy are used to probe the structure and function of a range of

objects, from small inorganic molecules to biological molecules and systems.

      New tools also provide the ability to manipulate and fabricate structures on this

scale. For example, SEMs can be used to create nanoscale patterns on a specially

prepared surface. This technology plays an important role in the miniaturization of

electronics as engineers work to create micro- and nano-electromechanical devices

(MEMS and NEMS respectively). In addition, it is now possible to manipulate matter at

the nanoscale. For example, modified SPMs enable scientists to investigate and

manipulate nanoscale entities such as adeno virus particles, DNA/protein complexes,

and mucin (ref nanoManipulator). In fact, scanning probe microscopes, albeit under

extreme conditions, can be used to move individual atoms into precise positions,

affording unprecedented control on the atomic level. Thus, these new tools and

instruments are a critical aspect of nanotechnology.

How can this fit into the curriculum?

      Much of the grade 7-12 science curriculum requires students to learn about

objects and phenomena that are too small to be seen with the naked eye. Beginning in

elementary school, students learn about the abstract concept electricity. In addition,

they are often introduced to atoms and atomic structure. As they learn about living

organisms, they study cells and even smaller things that govern the function of the cells

(mitochondria, proteins, DNA). Using tools to observe and measure these things that

are otherwise not visible may facilitate students’ conceptions of such abstract concepts.

For example, the change in voltage with resistance is predicted by the equation V = IR.
Using a voltmeter to observe the effect that changing the resistance in a circuit has in

the voltage output provides an experience that may enable students to derive the

mathematical equation that explains the phenomenon.

       While theory may have predicted the existence of atoms, experimental evidence

provided proof of their existence. Unfortunately, the historical experiments themselves

are somewhat abstract and may be less than convincing to students. The scanning

probe microscopes provide new, more accessible evidence for the existence of atoms. In

addition, the images provide evidence for the arrangement of atoms in a solid.

The tools that are available determine what scientists are able to observe and measure.

In the past, a need for a new tool was created by the desire to observe or measure a

predicted phenomenon. Thus for scientists, developing new tools or instruments is

often part of the experimental design. Therefore, this relationship between development

of tools and addressing a hypothesis is a key part of the scientific process.
LEARNING GOALS- TOOLS & INSTRUMENTATION

Big Idea- Development of new tools and instruments helps drive scientific
progress. Recent development of specialized tools has led to new levels of
understanding of matter by helping scientists detect, manipulate, isolate,
measure, fabricate and investigate nanoscale matter with unprecedented
precision and accuracy.



       The tools that are available determine what is accessible for scientists to study.

When new tools and instruments are developed, new worlds become accessible for

study. This accessibility leads to new understandings and new questions, which is part

of the scientific process. The development of tools has played an important role in

scientific progress throughout history. In the past, Galileo revolutionized our

understanding of the Universe after he studied the sky with his telescope. Likewise,

van Leeuwenhoek opened up the microscopic world and when he used the microscope

to examine a drop of water and saw that it was teeming with life. His studies provided

the first insight into the cellular basis of living organisms. A similar scientific

revolution is occurring now with nanoscale science. The rapid progress of the field is in

large part due to the development of new tools (e.g. atomic force microscope (AFM),

and scanning tunneling microscope (STM)) that have rendered the nanoscale world

more accessible.

       There are four major learning goals that are associated with the Tools &

Instrumentation big idea. They are all appropriate for grades 7-12. Focus can be placed
on different aspects the learning goals depending on the grade level and science context

(chemistry, physics or biology).

1. Specialized tools are required to detect, measure, and investigate the nanoscale
because structures on this scale are too small to be seen with optical microscopes.


2. Scientists and engineers developed specialized tools and techniques in order to
manipulate, isolate, and fabricate nanoscale structures.


3. Although nanostructures have always existed in Nature, scientists and engineers
were unable to study them, or to manufacture new nanostructures until advances in
technology allowed highly specialized, and sensitive tools to be developed.


4. The tools (e.g. AFM and STM) used to study and/or manipulate nanoscale structures
interact with individual atoms or nanoscale particles by means of electric forces.


General prerequisite knowledge-

       This set of learning goals requires certain prerequisite knowledge. For each of

them, students must understand that tools allow scientists to explore and investigate

the world. Quite often, the system that is a target for study is inaccessible in some way

(e.g. too far away, too small, too fast, etc.) so that scientists cannot study it using their

unaided senses. Throughout history, tools and instruments have been developed to

enhance the user’s senses. For example, telescopes and light microscopes enhance

vision. With these enhancements scientists can better describe, characterize, and

ultimately understand the world.
       All tools have limitations. The source of these limitations may be due to

technical limitations, or the system under investigation. Therefore, different tools are

better for different purposes. Choosing the correct tool to solve the problem at hand is

an important part of scientific practice.

     Size is the actual magnitude or amount of an object while the scale designates the

units by which the size is measured and thus describes the range of sizes. The

macroscale is generally considered to be the scale that can be experienced. The unaided

eye can resolve details approximately 0.2 mm (≥ 5 x 10-4 m). The sense of touch has a

similar limit; particles smaller than about 0.1 mm feel smooth (e.g. flour, powdered

sugar). The microscale is the next smaller scale that is visible only with a light

microscope. This is the world of cells and the organelles within them. Entities within

this world range in size from (10-7-10 –5 m). The nanoscale lies between the microscale

and atomic scale. Something is considered to be part of the nanoscale if at least one

dimension is one to 100 billionths of a meter (10-9-10-7 m). In order to understand these

definitions, students must have knowledge of the metric system so they can begin to

conceptualize the size of the nanoscale and how it relates to other scales. Different tools

are used at different scales to visualize and manipulate matter.



Learning Goal 1-
Specialized tools are required to detect, measure, and investigate the nanoscale
because structures on this scale are too small to be seen with optical microscopes.


What kids need to know/Clarification-
       Nanoscale objects are too small to see with the naked eye. In order to observe

something too small to see, the first thought might be to magnify it using magnifying

glass or optical/light microscope. However, as with all tools, optical microscopes have

limitations and these tools are only useful for observing objects larger than 0.2 µm.

Diffraction limits the resolution of these microscopes to about one half the length of

wavelength of the probing radiation. In this case, the radiation is visible light. The

wavelength of visible light visible light falls between about 400 and 700 nm, therefore

the smallest object that a visible light microscope can resolve is about 200 nm. The

nanoscale is defined to be 1-100 nm, therefore visible light microscopes are not useful

for studying the nanoscopic world. Therefore, scientists must use different tools in

order to investigate things on the nanoscale.

       Some of the tools use radiation, or light, with a smaller wavelength, which

enables smaller things to be studied. Scientists use X-rays to locate where the atoms lie

in a crystallized sample. In this way, they determine the structure of molecules. X-rays

have a wavelength of approximately 10-12 – 10-9 m so they can provide atomic resolution

since atoms are about 10-10 m in diameter.

       Scanning electron microscopes use a focused beam of electrons to scan the

surface of a sample. A high resolution, three-dimensional image is produced from

analyzing the electrons that are back scattered. The resolution of these microscopes can

be as high as 1 nm.

       Scanning probe microscopes (SPM) are quite different as they employ a physical

probe that scans the sample. Thus, these instruments enhance the sense of touch. The
probes consist of a very fine tip that is attached to a cantilever. The tip scans over the

surface of the sample, much like a finger reading a page of Braille. In this way, the

SPM’s produce an image of the sample surface. These microscopes have near atomic

resolution.



Prerequisite knowledge-
       The electromagnetic spectrum is the range of possible wavelengths of radiation,

or light. In order to observe an object, the wavelength of the radiation must be

approximately the same size or larger than the object itself. The range of wavelengths

in the spectrum spans from gamma rays which are less than 10-12 m to radio waves

which are 1- 104 m in length. Visible light is only a small portion of the spectrum (400-

700 nm). Radiation, or light, of other types can be used to study otherwise inaccessible

objects.



Potential student misconceptions-
• Students may believe that they can see atoms and molecules with a light microscope.


Learning Goal 2-
Scientists and engineers developed specialized tools and techniques to manipulate,
isolate, and fabricate nanoscale structures.

What students need to know-
       It is relatively easy for a man to use his hands to build a structure using bricks. If

the building blocks are too large (e.g. steel beams, concrete blocks), special tools or

machines are required to manipulate them. Likewise, when the building blocks are too
small, special tools are required to manipulate them in a controlled manner. For

instance, tweezers will facilitate the task of lining up grains of sand in a precise pattern.

The challenge is even greater for nanoscale objects. New instruments and techniques

allow scientists and engineers to work productively and efficiently at the nanoscale.

The new tools provide them with unprecedented control over the basic building blocks

of matter (atoms). Scientists can isolate and analyze nanoscale materials and

manipulate them in a controlled manner in order to fabricate new nanoscale structures.

Specific prerequisite knowledge-

none   (that I can think of at the moment)



Potential student misconceptions-

• There are not tools that are small enough to work with things that are too small to see.

Learning Goal 3
Although the nanoscale world has always existed in Nature, scientists and engineers
were unable to study it, or to manufacture new nanoscale structures until advances in
technology allowed the development of highly specialized, and sensitive tools.


What students need to know-
       Throughout history, the development of tools has initiated huge leaps in

scientific knowledge. The telescope opened up the universe beyond Earth and the

optical microscope led to profound changes in the understanding of the structure and

function of living organisms. As with these examples, the nanoworld has always

existed but little if anything was known about its contents before tools were developed

that made them accessible to study.
       One example is proteins, which are nanoscale objects that perform all of the

functions within living organisms that are necessary for survival. In the late 18th

century, protein was known as a biological substance with particular characteristics.

By the mid-nineteenth century, the elemental composition of proteins was identified. It

was not until the mid-twentieth century that it was conclusively proved that proteins

consist of chains of amino acids. In the 1960’s the first high (atomic) resolution protein

structure was determined using x-ray crystallography. Determining these structures has

provided great insight into how proteins function. Today, new tools such as cryo-

electron microscopy and atomic force microscopy (AFM) are pushing the

understanding of protein structure and function forward by giving near atomic

resolution in certain environments. This is just one example of the impact of new tools

and techniques on the progress of science. In particular, the development of scanning

probe microscopes, including AFM and scanning tunneling microscope (STM), has

rendered the nanoscale more accessible than ever before. It is these tools that are

driving the scientific progress behind the nanotechnology revolution.



Specific prerequisite knowledge-
       This learning goal could be used in a variety of science courses. For a biology
course, students would know that nanoscale objects such as proteins, DNA, ribosomes,
etc. are responsible for governing the processes of life. These objects have always
existed, but until recently, little was known about their structure. Natural nanoscale
objects are not only biological in nature. SOMETHING EARTH SCIENCE HERE.
Potential student misconceptions-
• Students may believe that optical microscope can be used to observe nanoscale
objects.
• Students may believe that miniaturized versions of familiar tools can be used to
manipulate matter at the nanoscale.


Learning Goal 4
The tools used to study and/or manipulate nanoscale structures interact with individual
atoms or nanoscale particles by means of electric forces.


What students need to know-
       The development of scanning probe microscopes allowed scientists and

engineers to study and/or manipulate matter at an unprecedented scale. While optical

microscopes extend the sense of sight by magnifying objects too small to be seen,

scanning probe microscopes extend the sense of touch. These microscopes make an

image of the surface of a sample by scanning an extremely sharp tip over the sample

surface. The process is much like using a finger to read Braille. Two of the most

common scanning probe microscopes are the atomic force microsopce (AFM) and

scanning tunneling microscope (STM).

       Since these microscopes are similar to the sense of touch, they actually interact

with the sample. The size of both the tip of the probe and the objects within the sample

are at the nanoscale. Electric forces dominate the interaction between objects of this size.

Thus, scanning probe microscopes



Specific prerequisite knowledge-
      All matter is made of atoms. Atoms contain a nucleus that is positively charged

and is surrounded by negatively charged electrons. The electron configuration,

particularly the outer electrons, determines the way the atoms interact with each other.

The same types of forces that bond atoms together also dominate interactions between

nanoscale objects. The range of way in which atoms interact through electrons creates a

continuum of electric forces.

Potential student misconceptions-
• Scanning probe microscopes work similarly to optical microscopes.
LINKS TO STANDARDS- Tools & Instrumentation

Big idea: Development of new tools and instruments helps drive scientific progress.
Recent development of specialized tools has led to new levels of understanding of
matter by helping scientists detect, manipulate, isolate, measure, fabricate, and
investigate nanoscale matter with unprecedented precision and accuracy.

From the earliest grades, students learn that one’s own hands have limits and that tools

are necessary in order to make certain things. Tools are not necessarily used only for

creating objects, but also to study them in order to understand them better.

      Tools are used to help make things, and some things cannot be made at all
      without tools. Each kind of tool has a special purpose. Benchmarks, 8B/3 K-2

      Tools are used to do things better or more easily and to do some things that
      could not otherwise be done at all. In technology, tools are used to observe,
      measure, and make things. Benchmarks, 3A/1 K-2

The tools that are developed extend the senses, enhancing vision, touch and hearing.

These tools play an important role in science because they allow scientists to measure

and observe things that are inaccessible without them. In addition, the advancement of

technology allows for the exploration of locations that are inaccessible in some way.

      Human beings have made tools and machines to sense and do things that
      they could not otherwise sense or do at all, or as quickly, or as well.
      Benchmarks, 6A/2 3-5

      Technology enables scientists and others to observe things that are too small
      or too far away to be seen without them and to study the motion of objects that
      are moving very rapidly or are hardly moving at all. 3A/2 3-5

      Measuring instruments can be used to gather accurate information for making
      scientific comparisons of objects and events and for designing and constructing
      things that will work properly. 3A/3 3-5

      Technology extends the ability of people to change the world: to cut, shape, or
      put together materials; to move things from one place to another; and to reach
      farther with their hands, voices, senses, and minds. The changes may be for
      survival needs such as food, shelter, and defense, for communication and
      transportation, or to gain knowledge and express ideas. 3A/4 3-5
Technology is constantly advancing, which also affects the development of tools. For

example, advancements in electronics have made it possible to continually make

smaller computers that have ever greater computing power.

       Technology is essential to science for such purposes as access to outer space
       and other remote locations, sample collection and treatment, measurement, data
       collection and storage, computation, and communication of information. 3A/2 6-

       Throughout all of history, people everywhere have invented and used tools.
       Most tools of today are different from those of the past but many are
       modifications of very ancient tools. Benchmarks 3A/1 3-5

       Science and technology often drive each other. The tools and instruments

available to scientists determine what is accessible for them to measure, and scientific

hypotheses and theories create a need for new tools and instruments. When new tools

and instruments are developed, new worlds become accessible for study. This

accessibility leads scientists to new understandings and new questions, which is part of

the scientific process.

       Science often advances with the introduction of new technologies. Solving
       technological problems often results in new scientific knowledge. New
       technologies often extend the current levels of scientific understanding and
       introduce new areas of research. NSES 9-12

       Technological problems often create a demand for new scientific knowledge,
       and new technologies make it possible for scientists to extend their research in
       new ways or to undertake entirely new lines of research. The very availability of
       new technology itself often sparks scientific advances. Benchmarks 3A/1 9-12

The development of new tools does not only affect scientific progress. Tools also play

an important role in manufacturing. New and better tools can help to improve

efficiency, quality and quantity of manufactured items.
Manufacturing processes have been changed by improved tools and
techniques based on more thorough scientific understanding, increases in the
forces that can be applied and the temperatures that can be reached, and the
availability of electronic controls that make operations occur more rapidly and
consistently. 8B/1 9-12

				
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