Inspiring, Machine learning, Thesis writing, Uncategorized

ESGI – A Different Type of Conference

Recently, I have attended 141th European Study Group with Industry (ESGI) conference in Dublin. It is a very different type of conference/workshop than what I have been attending so far. First of all everything is free, including food, coffee, snacks accommodation and registration – thanks to funding bodies SFI, UCD, MI-NET, MACSI. Second, it is a great opportunity to meet experts from different fields. Third, there are not so many talks or hurried people and most people are young post graduates and post-docs rather than professors. Everyone is there to learn rather than to advertise their work. More importantly, everything ran smoothly till the end of the conference.

The theme of the conference is that industries across Europe pose 5-6 challenges and 50-100 researchers from EU will solve these challenges in 5 days. It is something like a hackathon. This year, most of the problems from the industry are data science related. Since data science/machine learning is a hot topic, many people opted for these challenges. I opted for a Physics related challenge, that is related to wetting/wicking of rough surfaces. A semiconductor company has been looking for an optimised rough surface that can be wetted as easily as possible.


Wicking of Surfaces Decorated with Microplillars [1]

Although it seems simple at first glance, it is important to stress that by roughing a surface, wetting can be enhanced many orders of magnitude. For example, if we leave a water drop on a flat surface it takes up to 10 days to spread a diameter of 2cm. While using a optimised rough surface it takes only 10s. Such fast wetting of surfaces has applications in biomedical sensors where for example blood or urine samples can be reached to sensing regions easily.

This problem is interesting as it brought me back into the basics of physics, mainly fluid dynamics. Along with me, there are 13 members who liked this Physics challenge. So we formed as team that consists of 2 professors from Oxford. In the end only 5-6 people remained interested in the project and the rest slowly drifted away. Within our team, we formed sub teams, according to the level of expertise. I worked on my own as I don’t have any particular expertise in fluid dynamics.

Problems were given before we were going to the conference, so I did some back ground reading. In the first day itself, I met the company representative from the semiconductor company who gave this challenge. I expressed my interest to him. I read as many as 20 papers on this topic and came to a conclusion that the most of the things that the company would like to know about wetting of a rough surface were already studied/solved.

So I took the second day completely to read more literature and to make sense of it. On the third day, I narrowed down on 5-6 good papers and analysed them deeply. According to these papers, my conclusions are as following:

1) Critical angle of a drop on a rough surface depends on the roughness and it will be different than the critical angle on a flat surface.

2) The roughness dictates whether a surface can be superhydrophilc or superhydrophobic

3) Most rough surfaces studies are silicon cylindrical pillars on silicon substrate.

4) Dynamics of liquid spreading on a superhydrophilic rough surfaces follows washburn’s law i.e. the penetration length of the liquid front is proportional to the square root of time.

5) One can optimise the geometrical parameters such as height and diameters of the pillars and periodicity between the pillars to achieve faster spreading of a liquid drop on a rough surface.

Overall, we presented our findings. I made some friends. I enjoyed dwelling into other scientific field. I hope these type informal conferences will happen more frequently. I highly recommend my fellow researchers to attend the future ESGI conferences. I am looking forward to attend the next ESGI workshop.


Ishino, C., Reyssat, M., Reyssat, E., Okumura, K., & Quéré, D. (2007). Wicking within forests of micropillars. Epl, 79(5), 6–11.


Key lessons for start-ups

Recently, I have attended a start-up skills meet up organised by Scottish enterprise. One of the presenter is Kelvin, who has more than 20 years of experience as an inventor. The synopsis of his lecture are:

  • Start-ups should always advertise the benefits to the customers rather than the features of the product.
  • It is best to talk to relevant trade associations as they can introduce inventors to potential customers. This is a completely new perspective for me.
  • It is good to call the relevant people directly on telephone. People are willing to help most of the time.
  • We should do as many chicken gun tests (aka failure case studies) on the product before going big.
  • Asking right questions to customers for feedback, which gives invaluable insights for the product.
  • Knowing your business model is very important. One should know whether it is good to sell/rent/license their product.

In the next session, we leaned that there are more than one way of doing marketing. One of the best ways is third party referrals. So getting introduced by some known person would bring us many customers in less time. And it is especially true for start-ups which usually don’t have enough resources for marketing. Knowing the fears of potential customers is also important. It is winning over their fears that makes customers to buy our products. Mr. Kelvin emphasised that sending the demo product to potential customers and taking their testimonials would be one of the best strategy.


Raspberry Pi Robot Construction

Today, I am going to share the details of my  Raspberry pi Robot!

I have the following objectives in mind at the beginning of the project:

1) Construction should be simple, inexpensive and should have room for further development

2) It should have  video streaming capabilities.

3) I should be able to control the Robot from any smart device such as mobile, desktop or tablet

4) I should not install any new software on the controlling device

I am pleased that at the end of the project, I am able to achieve all these objectives.

In the following, I will give as many details as possible for the construction of my Raspberry Pi Robot!


1) Raspberry Pi

2) SD-card

3) Rechargeable Battery for Pi

4) Rechargeable batteries to drive the Motors

5) RC-car

6) L293D- IC

7) Bread board and some jumper wires

8) Wifi dongle

9) Webcam


Before going into details, I would like to show my Robot in action.


I disassembled  a old RC-car and removed the original controlling circuit inside of it. I just needed the bottom part of the car with motors and battery holder. This bottom part is our Robot Chassis. RC cars have mostly simple toy DC motors. The front motor is used for the left-right movement while the rear motor is used for the forward-backward movement.

I placed a bread board on the Chassis using foam glue tape. Then I placed raspberry pi on this breadboard at the front end of Chassis. I placed a L293D-Chip on the board at the rear end of the Chassis.

In the gap between the breadboard and front of the Chassis, I placed the rechargeable battery and the video camera. That’s it.

Circuit Connections:

Connections between RC-car and L293D

1) I saw the below video for connections from the L293D to the motors.

2) Basically each half of the chip controls one motor. First DC-motor of the RC-car will be connected to Pin 3 and Pin 6 of L293D. Second Motor will be connected to Pin 12 and   Pin 15 of L293D.

3) Pin 4,Pin 5, Pin 13, Pin 14 of L293D are connected to the ground line of the bread board.

4) The positive wire from the battery holder of the RC-car are connected to pin 16 of L293D, while the ground wire is connected to the ground line of bread board.

Connections between Raspberry Pi and l293D

Please be careful that I am referring here GPIO pin numbers on Pi, not the actual numbers on the board.

L293D PIN2 =GPIO  9
L293D PIN7 =GPIO 10
L293D PIN1 =GPIO 11

L293D PIN10 =GPIO  23
L293D PIN15 =GPIO 24
L293D PIN9 =GPIO 25

L293D PIN16 = 5V GPIO

Finally, connect  ground pin on Raspberry Pi to the ground line of the breadboard.

We may not need to use any solder, just jumper wires will be enough.


I used the Webiopi since it will provide simple interface for both the video streaming and controlling the motors with just a browser.

I followed the instructions from this blog for installing it. You will see pdf files of Mag Pi issue 9 and 10. I adopted the code, according to my RC-car chassis. Also, for some strange reasons, I am not able to get  my webcam working with mjpg streamer.

So I installed motion, which is very easy to use. I followed the instructions from this tutorial for installing motion.  I attached my files for controlling the RC-car here.

I also set-up the wifi on my Raspberry Pi using this guide.


Once after installing Webiopi, go to the folder where we downloaded the attached files on the Raspberry Pi. Just hit the following command

sudo python

Go to the browser on any device on your network, hit

http: //ip address of raspberrypi: 8001

In the above instead of “ip address of raspberry pi” use the actual ip address of your Pi. You should be able to see the video and four buttons to control the robot.

Some tips:

1) Please update your Raspberry Pi software. It drives me crazy with my old installation of Raspbain OS. I had to reinstall the latest version to make my webcam work.

2)   Increase the frame rates in the motion software or in mjpg software to get better streaming. Refer to this guide.

3) Make sure all the connections are made according to the GPIO numbers on the board, but not the physical pin numbers.

4) If you are trying to build the Robot from scratch, then try to divide the project into parts. Making all softwares  work together on Pi was the difficult step for me.

5) Please save all the settings of Pi, by cloning your SD-card using this guide.

Further improvements:

1) I wanna make it autonomous, by using ultra-sonic sensors

2) Adding Bluetooth control (both from mobile devices and PS3 controller)

3) Use a servo motor to rotate the webcam, so that we can see more area

4) Object tracking using Open CV

5) Using capacitors to have more safe connections.



Free Quantum Computing For Everyone

I almost shocked to know that, now if you want to play with a small quantum computer, you can do. If it is not a big happy shock, then hear it again. You can do it for completely free!

Yes, when I came to know about it, I was in disbelief. University of Bristol, developed a two-(qu)bit quantum computer. It has decided to give the access to this quantum computer, anybody who is interested in it. Basically University doesn’t sell the quantum computer. Instead it will let you use it over the cloud. How awesome it is?? However to get that access, one should come up with some interesting problem/algorithm.

Hey, don’t worry of you don’t have a killing unique idea. At least you can practice with their simulator for now. In the simulator, you can input some photons and adjust their phases and you will get some statistics at the output. If you are confident about your experiment in the simulator, you can then run the experiment on real quantum computer.  May be one day, who knows, you will be solving a big problem using the basics learned from these quantum computer experiments.

I know nothing much about quantum computers. But having studied the quantum mechanics and recently exploring  about the computers make me really excited about this! If you want to know more details of quantum computer, look at the links below.