Want to learn about 3D Printing - Try MIT Media Lab’s Mediated Matter's Course on 3D Printing

Want to learn 3D Printing and that too fast? Try out the course by MIT Media Lab's Meditated Matter group. The course is a collaboration with London’s Royal College of Art (RCA) Exploring Emergent Futures platform. Also, FormLabs, a MIT startup in the field of 3D printing has also associated with the project.
According to the course synopsis: “The MAS.500 Principles of Computational Design and Additive Manufacturing module will explore making through the lens of design, with a specific focus on designing for additive manufacturing. We will familiarize students with CAD software and computational design tools with which to create their own projects throughout the course of the module. Additionally, we will explore computational design and digital fabrication across multiple fields, including architecture, biology, and mechanical engineering. Students enrolled will gain insight into processes of digital and physical form finding and acquire skills that will be applicable across scales and disciplines. Students will be expected to complete a final video project linking the assignments for each session to demonstrate their understanding of the material.”

The sessions included hands-on tutorials in the Mediated Matter Lab space and the direct usage of various different prosumer 3D printers in Fused Deposition Modeling and Stereolithography 3D printing technologies such as the Makerbot Replicator 2 and Formlabs Form 1 machines. Given the speed of the course, as per the session schedule below, the results are on one hand exceptional, and on the other encouraging, as in it is indicative that when approached in the right way, desktop 3D printing and the surrounding skill set required for efficient usage can be learned in a short span of time.

Lecture 4 - Equilibrium

Thermodynamic Equilibrium: It is a combined state of Mechanical, Thermal and Chemical equilibrium.

Mechanical Equilibrium: The system has uniform pressure, i.e. no pressure difference between two interacting systems.

Thermal Equilibrium: The system has uniform temperature, i.e. no temperature difference between two interacting systems.

Chemical Equilibrium: There is no change in the composition of system, i.e. there is no tendency for a chemical reaction to occur.

Stability of Equilibrium states:

The above picture tells us about the different states of equilibrium. These are:

Stable: Where the system has a tendency to come back to its original position, no matter how large the displacing force is.

Neutral: It attains a new state when disturbed and remains in equilibrium there.

Metastable: On being disturbed by a very small disturbing force, it tends to come back to its original position i.e. acts as a stable system. But on application of large disturbing force, it gets displaced and do not comes back to original position.

Unstable: With a very slight displacement force gets displaced from its actual/original position and does not come back to its original position.

Equilibrium is more stable when it is lesser energy state, as all systems have a tendency to achieve the lowest energy state. The different types of Energies are:

1.       Potential - due to gravity ( = mgh)

2.       Kinetic- due to its velocity( = 0.5 *mv^2)

Mechanical Energy = Potential + Kinetic (Macroscopic State)

3.       Internal Energy (Microscopic State)

Types of Internal Energy: Translation, Rotational, Vibrational, Electron motion and Nucleus-nucleus interaction.

Thus, Total Energy = Kinetic + Potential + Internal

But in thermodynamics we study change of energy in a system where the Potential and kinetic energy of the system is constant. Thus we only consider changes in internal Energy.

Thus in thermodynamics,

Change in Energy = Change in Internal Energy.

Lecture 3 - Concept of State

The most Important concept in thermodynamics is the concept of State. If we knew the details of mass, velocity, volume, position and modes of motion of each molecule of the system then that knowledge would help us describe the details of the system at a microscopic level, and is known as microscopic state. But as we know getting such detailed information is not possible thus we rely on state parameters which describe the combined state of all molecules i.e. the macroscopic state . 

Thus,

Macroscopic State 

• Has a small no of variables are used to describe the state of matter.
• These variables are easy to measure.
• Structure of matter is not taken into account.

Microscopic  State

• It has a large no of variables.
• These variables can not be measured with current level of technology.
• The knowledge of the structure of matter is essential to analyze the behaviour of the constituent particles/molecules.

We consider here only Macroscopic state.

At first it might look like there a lot of variables which needs to be determined but in reality these variables are interdependent thus by fixing some of the variables, the values of rest of the variables get fixed. For a simple system with a given substance with a fixed composition we can fixed the system properties with just fixing two variables. These are known as Independent State Variables. 

• The minimum number of variables required to describe the state of the system are called independent state variables.

 We can choose any two properties/variables in case of gas, the variables most easy to control is Pressure and Temperature. Hence, let us take volume of a gas to be a fixed quantity and a function of Pressure and Temperature. Therefore,

V = V(P,T)

dV = (dV/dP)TdP + (dV/dT)PdT 

Now, we can determine how volume changes with Pressure and Temperature according to the function V. Thus, here V is dependent Variable and P and T are independent variable, used to describe the macroscopic state of the system.

Lecture 2 - Thermodynamic System

Thermodynamics deals with study of energy flow, and behaviour of matter. Where matter is anything that occupies space, and the region of matter which is subjected to thermodynamic analysis is called a system.
As system is a part of the universe, everything and anything other than the system is called the surrounding. Therefore,
System + Surrounding = Universe
We have mainly 3 types of system, based on the assumptions we take,

1. Open System : These are systems where both mass and energy can be exchanged with the surrounding. Eg. A bucket of steaming hot water - matter can escape in the form of steam and heat can flow out to the surroundings. 
2. Closed System : It is a system where only energy can be exchanged with the surrounding, i.e. exchange of mass is restricted by some means like a diathermic (which allows flow of heat through it ) wall or a container. Eg. If we pour the hot water in a air tight container and close it, no matter can go out but we do still feel the heat on the walls as heat can still flow out.
3. Isolated System : In this system neither energy nor matter can be exchanged with the surrounding. It can be assumed as a container with adiabatic walls( which restrict the flow of heat through it. This is an ideal case as a close to it example in real life is a thermos flask or vacuum flask, hot water kept in remains hot as the heat cannot flow out.

Some of the basics concepts and terms :-

• Extensive and Intensive Properties
• Extensive Properties : These are the properties which depend on the mass ( or size ) of the system. Eg. Volume ,Internal Energy, Entropy are extensive properties as their values depend on the size of the system
• Intensive Properties : These are the properties whose values are independent of the size of the system. Eg. Temperature and Pressure
• If Extensive properties are expressed as per unit mol or per unit volume, they have the characteristics of Intensive Properties. Eg. Mass is Extensive property but density is Intensive.

• Processes :

• Isothermal : A Process where the Temperature Remains Constant
• Isobaric : A Process where the Pressure Remains Constant
• Isochoric ( Isovolumic ) : A Process where the Volume of the System Remains Constant
• Adiabatic : A process in which there is no heat flow out the system, i.e. no exchange of energy in the form of heat with the surrounding.

Lecture 1 - Introduction to Metallurgical Thermodynamics

Thermodynamics deals with study of energy flow, and behaviour of matter. It can be broadly classified as :-

1.  Classical Thermodynamics(i.e. Macroscopic) :-  It is based on the 3 laws of  Thermodynamics, and we are not concerned with movement of particles and treat the medium as a continuum.
2. Statistical Thermodynamics :- It is based on Kinetic Law of Gases, considering individual particles and arrives at a macroscopic relation. 
3. Irreversible Thermodynamics :- As the name suggests it deals with the thermodynamics of Irreversible reactions

There are other classifications also like ,
1. Thermodynamics of non Reactive System
2. Thermodynamics of Reactive Systems

In the subsequent lecture notes, we will be concerned with Classical Thermodynamics only.

Lecture Notes Series

We are going to start a series of Lecture notes on subject relating to Metallurgy and Material Science. We are starting  off with two series of Lecture notes, one on Metallurgical Thermodynamics and the other on Physical Metallurgy ( basically, Introduction to Physical Metallurgy), and are looking forward to start a series on Electronic Materials.
Hope you all like these and find them useful. We are always happy to hear from you, so please comment any suggestions you have for us.