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Summer Internship Report Amratansh Gupta

1. INTRODUCTION

This internship began on May 27th 2016 and ended on July 15th 2016 as Device Development Intern

under Professor Ravikrishnan Elangovan at Indian Institute of Technology Delhi .I was selected for

the internship based on e-mail conversation with Professor Ravikrishnan Elangovan. This report talks

about the work done during summers as device development intern. I worked on:

I. Automation of diagnosis device for Immuno-Magnetic Cell Capture technique using

Raspberry Pi 2 model B with the help of programming language Python

II. Development of impedance measuring device for in vitro applications. (Stage -1)

2. Detailed Description:

I. AUTOMATION OF DIAGNOSIS DEVICE FOR IMMUNO-MAGNETIC CELL CAPTURE TECHNIQUE USING

RASPBERRY PI 2 MODEL B WITH THE HELP OF PROGRAMMING LANGUAGE PYTHON

Interfacing with Raspberry Pi 2 model B:

The initial stage of interfacing with Raspberry Pi 2 model B was a crucial part of project as it

developed my understanding with the device. The Raspberry Pi is a series of credit card-

sized single-board computers developed in the United Kingdom by the Raspberry Pi

Foundation. The Raspberry Pi 2 uses a Broadcom BCM2835 SoC with a 900 MHz 32-bit quad-

core ARM Cortex-A7 processor. In the initial days of this internship, I learnt the uses and

specifications of General Purpose Input Output (GPIO) pins, Raspian (Operating system) etc

and built the important concepts of Programming language Python. Raspberry Pi 2 provides

a platform to use multiple programming languages like JAVA and Python. I chose Python

over JAVA because of following reasons:

Availability of large number of Built-In Functions in Python

Python is a dynamically typed language whereas JAVA is statically typed.

Python is more compact and concise language than JAVA

Learning Programming language Python:

Learning a new programming language was almost a challenge for me as i have no prior very

strong background in the field of programming. C was the only language with which i was

familiar. I learnt Python using following resources:

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Python Documentation available on Internet:

https://www.python.org/doc/

Textbook: Head First Python ISBN-13: 978-1449382674

Massive Open Online Course(MOOC): Introduction to Computer Science and

Programming using Python - MITx - 6.00.1x

Automation of Stepper Motor:

A Stepper Motor or a Step motor is a brushless, synchronous motor which divides a full

rotation into a number of steps. Unlike a brushless DC motor which rotates continuously

when a fixed DC voltage is applied to it, a step motor rotates in discrete step angles. I

automated 4-wire stepper motor, which is going to be used as a movable magnet carrying

platform. Now, Stepper motor is capable of moving in forward as well as backward direction

with the variable speed in the precise number of steps using a 12V external supply. ‘Enable

pin’ is already provided to switch ON and OFF using the raspberry pi 2 through the Python

code. There is no need to switch off the stepper motor manually in order to save it from

excessive heating. This magnetic platform will help in the separation of injected cells from

the sample during diagnosis process.

Automation Process: With the help of motor Driving circuit L293N (consisting of dual H-

Bridge) and the GPIO pins raspberry pi 2 attained the control of 4-wire Stepper motor.

Python Code :

Refer to Python code file

Designing of Automated Temperature Sensor and Controller:

I automated a temperature sensor for measuring the temperature of the sample under

diagnosis precisely and employed peltier as a temperature controller with the help of

Raspberry Pi 2 and Python. The combination of peltier TEC1-12706 and temperature

sensor DS18B20, manufactured by ‘Dallas’, acted as a precise temperature measuring and

controlling device for the diagnosis of sample. This combination is able to control and

measure temperature up to 3 decimal places. The temperature is measured at every 1µsec

and displayed on the screen after every 100msec (can be change accordingly).The peltier

is used as a cooling and heating device, depending upon the direction of current flow.

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Access to python module ‘w1thermsensor 0.3.1’ for operating temperature

sensor DS18B20 on Raspberry Pi 2: For dealing with temperature sensor DS18B20, a python module is available which is developed by

Massachusetts Institute of Technology for usage of this sensor on Raspberry Pi.

Link: https://pypi.python.org/pypi/w1thermsensor

Python Code:

Refer to python code file

Note: The mentioned python code can be modified to use multiple temperature sensors

along with a peltier.

Automation of Piezo Micro Pump (mp6-DEM) using Raspberry Pi 2:

Maintaining a precise and constant flow rate of sample solution is a crucial process and it

needed to be very precise. I automated a Piezo micro pump that can maintain a constant

flow rate ranging from 50µl/min to 50ml/min using Raspberry Pi 2 and Python. The

micro pump is based up on the principles of Piezo effect and able to maintain the precise

flow rate.

Experiment to verify flow rate:

Different values of frequency is applied to the micro pump in order to measure the flow rate ( ml per

minute ) over a wide range.

a). Temperature Sensor DS18B20 (Left)

b). Peltier TEC1-12706 (Right)

a). mp6-DEM Micro pump device- external (Left)

b). Working Process (Right)

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Python Code:

Refer to code file

Python Code to execute all the above mentioned Python Codes:

A python code to execute all the above mentioned code is of great importance so that

Raspberry Pi 2 can have access and operate all the above mentioned sensors and devices

simultaneously.

Python Code:

Refer to Python Code File

II. DEVELOPMENT OF IMPEDANCE MEASURING DEVICE FOR IN VITRO APPLICATIONS. (STAGE -1)

In the first stage of this project, I read research papers on following:

Portable low cost cell impedance measuring device: The objective of this project is to

develop a portable low cost, multi frequency, portable cell impedance measuring device

with acceptable accuracy. The variation of impedance with the cell concentration is also a

means to detect the concentration of cells by measuring their impedance. I studied about

the various components of device separately.

After studying the research papers, I worked on the designing of variable frequency

generator.

3. CONCLUSION

The internship was indeed a great experience. I learnt a lot in the internship. I got an idea

how research based product are designed under the guidance of a prime institution. I also

experienced a new place and new atmosphere. I had a great time in summers and I indeed

learnt a lot of new problems and techniques. I hope that I will contribute more in the field of

electronics in future. I thank Professor Ravikrishnan Elangovan for giving me this

opportunity.