Closing the gap between man and machine
Biological systems depend on membrane receptors to communicate, while technology relies on electric fields and currents to transmit data—but scientists at the Lawrence Livermore National Laboratory have created a transistor modelled on living cells that it might allow electronic devices to be hooked directly to the nervous system. The transistor consists of two metal electrodes connected by a carbon nanotube, which acts as a semiconductor. The nanotube is layered with both an insulating polymer and a lipid bi-layer that mimics the structure around cell membranes, and the transistor is then powered by adenosine triphosphate (ATP)—the energy currency of living cells. When exposed to ATP, a protein in the lipid bi-layer acts as an ion pump, shuttling sodium and potassium ions across the membrane—so when both a voltage and an ATP solution (including the ions) are applied to the device, a current flows through the electrodes. The transistor is the first example of an integrated bioelectric system; a hybrid, half-man half-machine. The technology could be used to construct seamless bioelectronic interfaces, and even help human consciousness merge with technology—imagine being mentally linked to your laptop!