Photos: Low-cost tech aids basic needs

Human-powered pumps like this one enable people to retrieve water from seven metres deep. Pressure treadle pumps can divert water up a hill or into tanks above ground, ideal for farming. Costing between $12 (£6) to $80 (£40), these pumps marketed by IDE are used in Malawi, Zambia, Ethiopia, India, Cambodia, Nepal, Myanmar and Bangladesh.

Credit: International Development Enterprises