Smart materials

Date: 2015-10-07; view: 573.

Reading

Before you start

SMART MATERIALS

LESSON 3

Understanding Words and Phrases

The words or phrases that fit these definitions are underlined in the text you just read. Use the context to try to figure out their meanings, and match them with the given definitions, Write the words or phrases in the spaces provided.

Example: in large quantity, plentiful: a b u n d a n t

1. to be the basis (of something):

2. very large:

3. a difficult battle, a big effort:

4. generous to guests; favorable

to living: 4

5. deep, thorough, far-reaching:

6. formal discussion and debate

of an issue: 6

7. greatly pleased, very glad:

8. a chase, a search; a work

activity: 8

9. neutral, fair, not prejudiced:

10. independent, self-governing:

11. terribly hot and humid:

(ex. 1-5: White, L. Engineering p.5)

1. Read the sentences (1-3) below. What does the word smart mean in each one (clever, fashionable, or normal)?

1 He wore a smart suit to the meeting.

2 She's the smartest girl in her class.

3 They stayed in a smart hotel in New York

Look at the title of the text, Smart materials. Do you think the materials are clever, fashionable, or formal? Read the text and check.

Smart – or shape memory – materials are an invention that has changed the world of engineering. There are two types: metal alloys and plastic polymers. The metal alloys were made first and they are usually an expensive mixture of titanium and nickel.

Shape memory materials are called ‘smart' because they react to changes in their environment, for example:

- plastics that return to their original shape when the temperature changes. One use is in surgery where plastic threads ‘remember' the shape of a knot, react to the patient's body temperature and make themselves into stitches.

- metal alloys that have a ‘memory' and can return to their original shape. They are used in medical implants that are compressed so they can be put inside the patient's body through a small cut. The implant then expands back to its original shape. More everyday uses are for flexible spectacle frames and teeth braces.

- solids that darken in sunlight, like the lenses in some sunglasses.

- Liquid crystals that change shape and colour. These have been used in climbing ropes that change colour if there is too much strain and weight on them.

The future of these materials and their possible uses is limited only by human imagination. One clever idea is that if car were made of smart metal, a minor accident could be repaired by leaving the car in the sun!

3. Complete the definitions (1-8) below with the highlighted words in the text.

1 An___________is something medical put inside the body, e.g. a heart valve.

2 You need a good____________to think of new and interesting ideas.

3 The___________ is the first or earliest.

4 _______________are materials made from mixing two metals.

5 To_________means to become bigger.

6 To__________is to change because something else happens.

7 The___________is everything around a person or thing.

8 To be __________means to be made smaller.