American researchers have created a biological chip powered by energy-generating systems in a cell.
The team from Columbia University managed to integrate a regular CMOS integrated circuit into an artificial lipid membrane containing ATP-powered ion pumps.
The system is one of the first containing both biological and solid-state components on a molecular level.
"In combining a biological electronic device with CMOS, we will be able to create new systems not possible with either technology alone," explained Ken Shepard, Professor of electrical and biomedical engineering at Columbia University who lead the research described in the latest issue of the journal Nature Communications.
"We are excited at the prospect of expanding the palette of active devices that will have new functions, such as harvesting energy from ATP, as was done here, or recognizing specific molecules, giving chips the potential to taste and smell. This was quite a unique new direction for us and it has great potential to give solid-state systems new capabilities with biological components."
ATP, or adenosine triphosphate, is an enzyme in cells responsible for transporting energy from where it is generated to where it is needed. In the prototype biological microchip created by the Columbia team, ATP is generated by a biocell that pumps ions across the lipid membrane to produce an electrical potential that can be harvested by the CMOS integrated circuit.
"We made a macroscale version of this system at the scale of several millimetres to see if it worked," Shepard said. "Our results provide new insight into a generalised circuit model, enabling us to determine the conditions to maximize the efficiency of harnessing chemical energy through the action of these ion pumps. We will now be looking at how to scale the system down."
While other groups have harvested energy from living systems, Shepard and his team are exploring how to do this at the molecular level, isolating just the desired function and interfacing this with electronics. "We don't need the whole cell," he explained. "We just grab the component of the cell that's doing what we want. For this project, we isolated the ATPases because they were the proteins that allowed us to extract energy from ATP."
The ability to build a system that combines the power of solid-state electronics with the capabilities of biological components has great promise. "You need a bomb-sniffing dog now, but if you can take just the part of the dog that is useful - the molecules that are doing the sensing - we wouldn't need the whole animal," said Shepard.
"With appropriate scaling, this technology could provide a power source for implanted systems in ATP-rich environments such as inside living cells," added Roseman.