ALEXANDRIA, Va., Feb. 26 -- United States Patent no. 12,235,234, issued on Feb. 25, was assigned to TIANMA JAPAN LTD. (Kanagawa, Japan).
"Ion sensing device" was invented by Hiroyuki Sekine (Kanagawa, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "Ion sensing device includes a field-effect transistor including a bottom gate and a top gate, a reference electrode, and a driver circuit configured to measure concentration of ions in a sample solution into which the reference electrode and the top gate are immersed. The driver circuit includes a constant current source configured to supply a drain of the field-effect transistor with a constant current, and a voltage follower configured to receive a potentia...