Question: What is the invention of the social entrepreneur whose life is the subject of an upcoming 2018 Indian film called 'Padman' ?

Context articles: Aschhe Abar Shabor
Arunachalam Muruganantham
Mogul (film)
Verghese Kurien
Bharat Ane Nenu
Karwan (film)
Paul Garrin
John Merrick (insurance)
Padman
Gold (2018 film)

Aschhe Abar Shabor (Bengali: আসছে আবার শবর ; ) is an upcoming 2018 Indian Bengali-language crime thriller film directed by Arindam Sil.
 It is the sequel to 2016 film "Eagoler Chokh" and the third installment of "Goenda Shabor" film series.
 The film is scheduled to release in January 2018.
 The film is based on a story "Prajapatir Mrityu O Punorjanmo", written by Shirshendu Mukhopadhyay.
Arunachalam Muruganantham (born 1962) is a social entrepreneur from Coimbatore in Tamil Nadu, India.
 He is the inventor of a low-cost sanitary pad making machine and has innovated grass-roots mechanisms for generating awareness about traditional unhygienic practices around menstruation in rural India.
 His mini-machines, which can manufacture sanitary pads for less than a third of the cost of commercial pads, have been installed in 23 of the 29 states of India.
 He is currently planning to expand the production of these machines to 106 nations.
Mogul - The Gulshan Kumar Story is an upcoming 2018 Indian biographical film written and directed by Subhash Kapoor and produced by Bhushan Kumar.
 The film is based on the life of Gulshan Kumar who was founder of the T-Series music label (Super Cassettes Industries Ltd.), and a Bollywood movie producer.
 The film is set to release in 2018.
Verghese Kurien (26 November 1921 – 9 September 2012) known as the "Father of the White Revolution" in India was a social entrepreneur whose "billion-litre idea", Operation Flood - the world's largest agricultural dairy development programme, made dairy farming India's largest self-sustaining industry and the largest rural employment provider, being a third of all rural income, with benefits of - raising incomes & credit, riddance of debt dependence, nutrition, education, health, gender parity & empowerment, breakdown of caste barriers and grassroots democracy & leadership.
 It made India the world's largest milk producer, surpassing the United States of America by 1998, with about 17 percent of global output in 2010–11, from a milk-deficient nation, which doubled milk available per person and increased milk output four-fold, in 30 years,
Bharat Ane Nenu is an upcoming 2018 Indian Telugu-language political thriller film directed by Koratala Siva, featuring Mahesh Babu and Kiara Advani in the lead roles.
Karwan is an upcoming 2018 Indian Bollywood comedy film, directed by Akash Khurana and produced by Ronnie Screwvala.
 The film is scheduled to release sometime in 2018.
 Dulquer Salmaan is making his debut in Bollywood with the film.
Paul Garrin (born 1957) is an interdisciplinary artist and social entrepreneur whose work explores the social impact of technology and issues of media access, free speech, public/private space, and the digital divide.
 Starting as his assistant in 1981, Garrin eventually emerged as one of the important collaborators of video art superstar Nam June Paik, working closely from 1982 to 1996.
John Merrick (1859–1919) was an African-American entrepreneur whose life represents a rags-to-riches story.
 Born into slavery in Clinton, North Carolina, Merrick relied on his social savvy, entrepreneurial spirit, and inner drive to achieve great personal wealth by founding various companies in the Raleigh, North Carolina and Durham, North Carolina areas, most notably the North Carolina Mutual Life Insurance Company.
 Portions of his wealth were channeled back into the black community through philanthropy.
 John Merrick was a great man- his business acumen and social consciousness made him one of the most influential members of the African-American community in his lifetime.
Padman is an upcoming 2018 Indian Hindi comedy-drama film featuring Akshay Kumar, Sonam Kapoor and Radhika Apte in lead roles.
 Amitabh Bachchan will appear in a special role.
 The film is inspired from the life of Arunachalam Muruganantham.
Gold is an upcoming 2018 Indian sports film, directed by Reema Kagti and produced by Ritesh Sidhwani and Farhan Akhtar under the banner Excel Entertainment.
 It is a biopic based on the life of hockey player Balbir Singh, who was on the team that won the first Olympic medal for India as a free nation in 1948.