MEMS optical liquid level sensor
US11161110B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 2018 |
| Grant date | Nov 2, 2021 |
| Priority date | — |
| Expiry date | Aug 15, 2039 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01L2300/0663
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Microfluidic chips incorporating liquid level sensors for precise sensing of liquid levels in microfluidic system structures, e.g., channels, cavities or reservoirs without moving parts. The microfluidic system uses liquid level photosensors and use optical properties to measure liquid volumes. A light coupling emitter or waveguide transmits the light toward the fluid channel at a critical angle. Multiple light coupling emitters and photosensor array can detect light for a variety of scenarios (based on fluid refraction index) and exploit the phenomenon of critical angles to measure exact angles of reflection/refraction. The waveguide coupler(s) and photosensors are manufactured at the microscale, and use both reflected light and refracted light as monitor signals. A feedback control system (e.g., compensating for rate and tolerance drift) is devised using signals generated by the sensors upon detecting reflected or refracted sensed light for increased accuracy of detecting precise amounts of fluid volumes being dispensed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.