A Sperm Testing Device on a Liquid Crystal and Polymer Composite Film

Abstract

Developing a handy sperm testing device is important since sperm quality is a significant factor for fertility potential. In this paper, we demonstrate a sperm testing device based on a switchable surface, a liquid crystal and polymer composite film (LCPCF). The wettability of LCPCF is electrically switchable due to the electrically tunable orientations of liquid crystal molecules. In experiments, two motions of a semen drop on switchable surface of LCPCF are observed: back-and-forth stretches and collapses of semen drops. The better quality spermatozoa results in back-and-forth stretches of a semen drop on LCPCF; otherwise, the semen drop collapses. The motility and concentration of semen can also be sensed by the stretch distance and collapse distance of semen drops, respectively. The mechanism of back-and-forth stretches of semen drops results from fertile sperms swimming against the flow with the periodic changes of the orientation of LC molecules with pulsed voltages. The mechanism of collapses of semen drops results from the washed-away infertile sperms which are deposited on LCPCF and then re-modify surface of LCPCF. Potential applications for this device include sperm testers and microfluidic devices for Assisted Reproductive Technology.

Liquid Crystals for Bio-medical Applications

“…The LCPCF can sense the semen through the motion of a semen droplet which in turn depends on the information of spermatozoa in the semen. We first demonstrated a sperm testing device by either a back-and-forth stretch or a collapse of a semen droplet on LCPCF [20]. The sperm sensing mechanism of LCPCF is depicted in Fig.…”

“…The better quality spermatozoa results in back-and-forth stretches of a semen drop [20] on LCPCF; otherwise, the semen drop collapses. From the experimental results, stretching of a semen droplet indicates the high concentration (>100 million/ mL), good morphologies (>15 %), good motility (>50 %) of spermatozoa, and more than 30 % of spermatozoa swimming jointly forward.…”

“…In order to sustain thermotropic nematic LC materials, LC and polymer complex systems are great candidates to turn the soft LC materials into film-like structures which are easy to apply voltage to further stimulate the LC orientations for biosensing. Recently, we develop a LC and polymer composite film (LCPCF) whose wettability (or surface free energy) is electrically tunable due to the orientation of LC molecules on LCPCF [16][17][18][19][20][21]. LCPCF is a film fabricated through photoinduced phase separation process.…”

“…15.5c. The hysteresis of LCPCF, [20] the difference between advancing (~64°) and receding angle (~52°), is ~12°. After 0.65 s, the water droplet slides toward the smaller contact angle on the left.…”

A droplet manipulation on a liquid crystal and polymer composite film as a concentrator and a sun tracker for a concentrating photovoltaic system

“…In these years, we developed a liquid crystal and polymer composite film (LCPCF) whose surface free energy is switchable owing to LC orientations and several applications based on droplet manipulation on LCPCF were developed as well, such as electro-optical switches, sperm testing devices, and liquid lenses. 16,[20][21][22][23][24] In this paper, we demonstrate a CPV system with a steady output electric power. The curvature of the liquid lens can be adjusted to affect the concentration ratio and the position of the liquid lens can also be bistably controlled to track the sunlight.…”