  We demonstrate topological insulator (Bi$_2$Te$_3$) dc SQUIDs, based on
superconducting Nb leads coupled to nano-fabricated Nb-Bi$_2$Te$_3$-Nb
Josephson junctions. The high reproducibility and controllability of the
fabrication process allows the creation of dc SQUIDs with parameters that are
in agreement with design values. Clear critical current modulation of both the
junctions and the SQUID with applied magnetic fields have been observed. We
show that the SQUIDs have a periodicity in the voltage-flux characteristic of
$\Phi_0$, of relevance to the ongoing pursuit of realizing interferometers for
the detection of Majorana fermions in superconductor- topological insulator
structures.
