Abstract: Examples of the disclosure are directed to the use of one or more piezoelectric (PE) transducers for detecting one or more touches on a surface. In some embodiments, the one or more PE transducers can complement a capacitive touch sensor array and provide a confirmation that a touch has in fact occurred, and can provide a secondary determination of touch location. In some examples, the one or more PE transducers can be formed on, or as part of, a flex circuit that is adhered to a housing or other structure to which the touch surface is affixed. The flex circuit can be formed as a strip upon which the one or more PE transducers are attached, and can be shaped and sized (optionally with a fold to create a tail for electrical connections) to adhere to an inner or outer surface of the housing.

Abstract: Microfabricated particulate matter (PM) monitors and fractionators within the PM monitors are provided. A primary channel of a vertical or out-of-plane fractionator receives air samples, comprising particles of varying sizes, from the external environment. The air samples then pass through a plurality of microfluidic channels, wherein inertial forces are applied within the microfluidic channels to separate the particles by size. The fractionator comprises a horizontal air outlet for particles having a size below a threshold size and a vertical air outlet for particles having a size above a threshold size. Thus, the proportion of PM in the air sample is reduced prior to deposition on a PM monitor. A virtual cyclone may also be provided that comprises a bend positioned at a flow path through a primary channel of the vertical microfabricated fractionator.

Abstract: The present disclosure provides for a system and method of concentrating airborne particles, specifically toward the center of one or more intake channels of PM sensors. The invention provides a simple and cost effective device that, when used in conjunction with a MEMS PM sensor or the like, can increase the sensitivity of said device by orders of magnitude. An in-line MEMS PM concentrator uses a converging optical intensity field to concentrate particulate matter along the center of a longitudinal axis of a microchannel. More specifically, the concentrator is designed to bring in ambient air containing PM through a microchannel and concentrate the PM in the center of the microchannel using a converging optical intensity field within a confocal optical cavity.

Abstract: Microfabricated PM sensors measure concentrations of particulate matter (PM) in air. Some sensors improve the accuracy of measurements by accounting for the effect of ambient conditions (e.g., temperature or humidity) on mass-sensitive elements employed to determine a mass of the PM in a stream of air. Some sensors improve the accuracy of measurements by controlling humidity in the stream of air measured by mass-sensitive elements. Some sensors employ a plurality of mass-sensitive elements to extend the useful life of the PM sensor. Some sensors employ one or more mass-sensitive elements and heating elements to cause deposition and allow measurement of different sizes of PM. Some sensors can measure mass concentration of coarse PM in addition to fine PM in a stream of air. Some sensors control the flow rate of a stream of air measured by mass-sensitive elements. Some sensors include features to mitigate electromagnetic interference or electromagnetic signal loss.

Abstract: Microfabricated particulate matter (PM) monitors and fractionators within the PM monitors are provided. A primary channel of a vertical or out-of-plane fractionator receives air samples, comprising particles of varying sizes, from the external environment. The air samples then pass through a plurality of microfluidic channels, wherein inertial forces are applied within the microfluidic channels to separate the particles by size. The fractionator comprises a horizontal air outlet for particles having a size below a threshold size and a vertical air outlet for particles having a size above a threshold size. Thus, the proportion of PM in the air sample is reduced prior to deposition on a PM monitor. A virtual cyclone may also be provided that comprises a bend positioned at a flow path through a primary channel of the vertical microfabricated fractionator.

Abstract: The present disclosure provides for a system and method of concentrating airborne particles, specifically toward the center of one or more intake channels of PM sensors. The invention provides a simple and cost effective device that, when used in conjunction with a MEMS PM sensor or the like, can increase the sensitivity of said device by orders of magnitude. An in-line MEMS PM concentrator uses a converging optical intensity field to concentrate particulate matter along the center of a longitudinal axis of a microchannel. More specifically, the concentrator is designed to bring in ambient air containing PM through a microchannel and concentrate the PM in the center of the microchannel using a converging optical intensity field within a confocal optical cavity.