NASA has awarded a $2 million project to Purdue University for a microsatellite experiment to determine how plant cells react to different gravity situations.

Marshall Porterfield, a professor of agricultural and biological engineering and horticulture and landscape architecture, is developing lab-on-a-chip technology that allows for the study and measurement of microscopic cellular samples. Porterfield's lab on a chip will use fern spores as a model to observe how gravity affects calcium signaling activity.

Calcium activity is associated with polarity - the directions sprouts and roots will grow during germination. Understanding how gravity affects calcium signaling is important for determining conditions necessary to grow plants in space.

"We may have to use some sort of artificial gravity to keep plants growing properly in space," Porterfield said. "Calcium signaling acts as a compass for these fern spores."

These microfabricated lab-on-a-chip experiments will be sent into space on a microsatellite using leftover launch capacity that goes unused when larger satellites are sent into orbit. Lab-on-a-chip systems are fabricated on silicon disks using some of the same techniques used to make microprocessors and include small pores with microsensors to hold the fern spores.

This is referred to as a Bio-CD because the disks can be rotated to create centrifugal force to mimic gravity in outer space. The faster they spin, the more gravity is created for the fern spores.

Microelectrodes outside the pores will gather signaling information and transmit it back to Earth. Porterfield wants to know how much gravity is necessary to turn on the calcium signaling activity.

Porterfield said interdisciplinary research among fields in the life sciences and engineering will be key to the experiments. The work will span both the Birck Nanotechnology and the Bindley Bioscience centers in Discovery Park, Purdue's large-scale interdisciplinary research complex.

The NASA project is the first major program for the Birck Bio-Nano Integration Laboratory, the only university-run facility of its kind that combines biology and nanotechnology.

"This really highlights the type of dynamic collaborations that are possible here at Purdue," Porterfield said.