Twenty-five inventors from across the country have gathered at Rashtrapati Bhavan to showcase their grassroots innovations. Looking at the 41 innovations it was hard to imagine that the hands which have made them had little or no formal training in science and technology.

The seven-day event, which is being held every year since 2010, was inaugurated by President Pranab Mukherjee on Friday. The participants have come from various states, including Karnataka, Jammu & Kashmir, Uttar Pradesh, Gujarat, Manipur and their work ranges from agricultural to daily household products, for the annual National Innovation Foundation-India.

For the visitors, a range of innovations are on display — from a three-wheeled harvester to crockery made of clay; silk reelers; laminators that work on solar power; and much more.

Employees of Dipakbhai Vyas, owner of a cotton-wick store in Ahmedabad, would complain of rashes during production. The employees, especially women, would get rashes due to the daily rolling of cotton between their fingers. Vyas said that he started working on a protype in 2009 that could roll cotton wicks faster without causing any inconvenience to the worker. Now after five years of experimenting, Vyas has made a machine-the size of juicer-that rolls 20-25 wicks in a minute, compared to 8-10 manually. Besides supervising work back at his store, Vyas is now also selling this machine, which he says has no rival in the market at the moment. The machine has been priced at Rs 7,500.

Ram Sanjeevan, a farmer from Gonda in UP, couldn't water his paddy entirely in summer. The traditional sprinklers would just cover a limited area, and needed to be moved across the field. Sanjeevan then came up with 'Meghraj', a mobile sprinkler which can move about its axis and also along a circular rail on which it is mounted. Surprisingly, this device can cover up to 100 feet in a few minutes. "I have applied for a patent and also received a number. I will be tying up with companies soon to sell my innovation at a good price," says Sajeevan.

Entry to the exhibition is through Gate No 35, between 10am and 4pm, a statement released by Rashtrapati Bhavan said.