A method of tuning a one-dimensional guided-mode resonance grating through the use of an air-pressure-responsive membrane is demonstrated here using finite-element method simulation. The device consists of a titanium dioxide ( ${\mathrm{TiO}}_2$ ) grating structure embedded in a flexible polydimethylsiloxane membrane. This grating has a resonant response to TM-polarized light at a wavelength dependent upon the refractive index of the surrounding medium. By varying the pressure by $5500\mathrm{Pa}$ , lateral strain may be applied to the grating; this allows resonances to be produced for medium refractive indices ranging from 1.33 to 1.50 for a fixed-wavelength $850\mathrm{nm}$ light source.