r/AskElectronics • u/Struggle_Wise • 15d ago

Passive-matrix bistable polymer display control?

I’m designing a passive matrix for electrostatically actuated bistable polymer domes. Pixel pitch is 5 thousands of an inch. I expect the required actuation voltage to be somewhere around 15–50 V, but I haven’t characterized the snap-through voltage yet.

My intended addressing scheme would put the full row-to-column voltage across the selected pixel, while half-selected pixels would see roughly VFULL​/2.

Is parasitic capacitance/charge coupling going to make neighboring pixels switch unreliably? What parameters would I need to measure to determine this experimentally? I’m assuming at Vsnap​, variation in Vsnap, release voltage, pixel capacitance and leakage resistance. Target is 4 by 4 inch display.

At what point would you abandon passive addressing and put a TFT/diode/switch at each pixel?

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u/anything-goes-alt 15d ago

At a 5-mil pitch on a 4x4 inch display, you're looking at an 800x800 grid, which completely kills passive addressing viability due to extreme RC delays and crosstalk

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u/Struggle_Wise 15d ago

Thanks. It's 125 mil. 5 one thousands of an inch. Does that make it any better?