At the end of my first year of undergraduate, I, with three of my hostel-mates, signed up for ITSP: Institute Technical Summer Project. ITSP was a great program where the institute would fund ~70 USD to students to build anything they want.
Being young naïve kids, we decided to be ambitious and aimed to build a bot that can climb walls. Now this was an ambitious undertaking because no such bot had been built before in our institute. So there was no precedence if such a bot can be built within the budget and we had no one with relevant expertise to mentor us.
While the above challenge is very clear in hindsight, while choosing our project we were terribly overconfident and blind to any possible failures. Despite our naivety, it is surprising that we were able to build a working model! That too with an out-of-the-box design to keep it within the budget.
Here is a short clip:
The basic idea was simple: The bot would stick to the walls via suction cups. The suction cups were connected to pumps that would pull the air in and out to make them stick and ‘un-stick’. Finally, the top suction cup was attached to the main body with a motor, so that it can pull up the main body along the wall.
Our main innovation was not so much in the design but in implementing it using parts that are readily available in the market. In particular, the suction cups were torn from those used on wall hangers, while the pumps were built by cleverly connecting medical syringes with motors. These ‘jugaad’ allowed us to build our bot for under 50 USD!