We report on the development and experimental evaluation of bi-SQUIDs with sub-micron cross-type shunted Josephson tunnel junctions characterized by low capacitance. Such a technology meant for SQUID sensors, was developed in order to enable unshielded operation of the sensors and to avoid unwanted flux trapping. Voltage response swing as high as 60 μV was observed for the fabricated bi-SQUIDs. The improved gradiometric-type design of bi-SQUIDs is developed to compensate the observed influence of the parasitic 3-junction loop and to improve the bi-SQUID characteristics by decrease in the inductance value.