The workshop began in mid-July, with the arrival of nearly 50 visitors from Brazil, Ghana, Guatemala, Tanzania, Tibet and other countries.

Most of the $200,000 budget was provided by donations from individuals and private groups, including the National Collegiate Inventors and Innovators Alliance, which supports university programs to develop commercially viable products that advance society.

The workshop began with a lecture by Paul Polak, a psychiatrist turned entrepreneur, who develops simple solutions for the problems of the poor. Dr. Polak, who has become something of a guru to the design revolution movement, railed against conventional charity and insisted that the route to prosperity lies in inventions that improve lives but mesh with existing lifestyles.

He laid out the principles of development from the bottom up, including the importance of first listening and watching, then following the old dictum “small is beautiful” with another, equally important one: “cheap is beautiful.”

The goal, he said, should be to improve a million lives, and to make technologies that can be sold and bought in increments — like a drip-irrigating system that can expand as a farmer’s income rises. Dr. Polak said in an interview that at least in the classroom, the push for such initiatives was coming from young people.

Ms. Smith said she wanted to avoid having the workshop end up as yet another academic exercise where the only outcome is often a set of paper proceedings or pledges. This time, she said, the goal was “no paper, just prototypes.”

Image Mohamed Mashaal, right, a British engineer, testing a plastic backpack with his design partner, Bernard Kiwia, who hopes people in Tanzania can use it to haul water over long distances. Credit... Andrew C. Revkin/The New York Times

In fact, in the first days of the workshop, it seemed that the only paper in evidence was an ever-spreading, flower-petal array of blue, green, pink and yellow sticky notes on walls and blackboards. The notes charted the progression from basic needs (water, food, energy, health) to specific issues (a three-mile hike to and from the nearest water supply in a Tanzanian village, the lack of a well-testing kit that a Bangladeshi village clinic could afford).