The ASPIRE devices were first fabricated on planar substrates to validate the solution-processability and mid-IR electrochromic performance. As shown in Fig. , the planar ASPIRE device can be tuned between a low-emissivity (oxidized/doped) state and a high-emissivity (reduced/dedoped) state, using chronoamperometry (CA) in a two-electrode configuration. The FTIR results confirm that the structural design effectively facilitates ion transport from the hydrogel electrolyte to the outermost layer of PEDOT:PSS, enabling electrochromic performance. An operational potential window of ±2 V was chosen for the subsequent experiments to maximize the IR tuning performance. A constant potential of 2 V (for low-ε/doped state) and -2 V (for high-ε/dedoped state) was supplied for 5 minutes each, totaling 10 minutes per cycle to ensure complete reduction or oxidation of the top layer of PEDOT:PSS.