This work explores reconfigurable circuits operating at low voltages. While the existing FPGAs are too high power to meet the requirements of IoT applications, we designed and optimized new circuit typologies of CLBs and global interconnect in near/sun-threshold region. We also developed custom tool flow to support full chip configuration. A 90nm chip implements the FPGA with 1134 LUTs, which is 2.7X smaller, 14X faster, and 4.7X less energy than a sub-threshold FPGA using conventional circuits and 22X less energy than an equivalent FPGA at full VDD. We are currently working towards dynamic voltage scaling and measurements using real-life applications.