We propose a reflective display device using an array of encapsulated micro droplets
of a room temperature ionic liquid mixed with pH indicator dyes.
The array is embedded in and addressed by a passive matrix.
Parylene- on-liquid deposition is employed to encapsulate the liquid droplet arrays.
When applying current to each droplet, the liquid mixture changes its color,
providing the ability to display a pixel of graphics information.
Once changed, the droplets can be tuned back to their initial color
by reversing the direction of the applied electric current.
The on-off switching time is less than 0.5s.
The response speed of the devices is at least 2Hz.
Nguyen Binh-Khiem, Kiyoshi Matsumoto, Isao Shimoyama, “Reflective display using ionic liquid,” 22nd IEEE International Conference on Micro Electro Mechanical Systems (MEMS '09), pp. 168-171, Sorrento, Italy, 2009.