Résumé : A broadband and temperature tolerant liquid- controlled adiabatic waveguide coupler (LCC) is realized. The LCC with silicon nitride (SiN) waveguides is designed to be com- patible with liquids that can be actuated by an electrowetting-on- dielectric (EWOD) system. This proof-of-principle demonstration with manual actuation paves the way towards the realization of non-volatile optical switch systems. A 630 μm long LCC configured as a 1 × 2 switch has a measured insertion loss less than 1.5 dB and a crosstalk less than -14 dB for both bar and cross state over the telecommunication wavelength range 1260 nm to 1630 nm. Furthermore, the LCC is tolerant to variations in temperature. The measured excess insertion loss over the temperature range 21°C to 73°C is less than 0.3 dB for bar and cross state, over the same wavelength range.