An adaptive ISFET chemical imager chip

A CMOS based ion sensitive chemical imager chip is presented for real time spatio- temporal monitoring of chemical activity. Ion-sensitive field effect transistors (ISFETs) implemented on an unmodified process (AMS 0.35 um) are used as the chemical input to the analogue circuits. A 3 x 11 array has been designed and fabricated for monitoring applications such as cell metabolism and growth. Chemical sensor information is encoded using integrate and fire neurons with address event representation (AER) used to fan out the data. Global adaptive biasing of pixels is used to conserve power and allow automatic functionality in changing buffer concentrations.