A method of detecting a particle comprises magnetizing a particle using an AC magnetic field; generating an AC voltage in a sensing device having a conductive substantially 2-dimensional lattice structure from the magnetized particle; superimposing a DC magnetic field on the generated AC voltage in the sensing device; and measuring an AC Hall voltage at the sensing device.

A method of detecting a particle comprises magnetizing a particle using an AC magnetic field; generating an AC voltage in a sensing device having a conductive substantially 2-dimensional lattice structure from the magnetized particle; superimposing a DC magnetic field on the generated AC voltage in the sensing device; and measuring an AC Hall voltage at the sensing device.

A method of detecting a particle comprises magnetizing a particle using an AC magnetic field; generating an AC voltage in a sensing device having a conductive substantially 2-dimensional lattice structure from the magnetized particle; superimposing a DC magnetic field on the generated AC voltage in the sensing device; and measuring an AC Hall voltage at the sensing device.

A method of detecting a particle comprises magnetizing a particle using an AC magnetic field; generating an AC voltage in a sensing device having a conductive substantially 2-dimensional lattice structure from the magnetized particle; superimposing a DC magnetic field on the generated AC voltage in the sensing device; and measuring an AC Hall voltage at the sensing device.

The present disclosure is directed to systems and methods for measuring airflow. In one example, an airflow monitor includes an ion generator positioned in a controlled space, an ion detector positioned in the controlled space and spaced from the ion generator, and a controller configured to receive a signal from the ion detector, to measure a time between emission of ions from the ion generator and detection of ions at the ion detector, and to calculate a speed of airflow between the ion generator and the ion detector based on the measured time.

A microfluidic electrochemical device has a microfluidic channel and an electrochemical cell having a pair of working electrodes separated by an inter-electrode distance in a flow direction of the fluid in the microfluidic channel, a counter-electrode and a reference electrode. The microfluidic electrochemical device has an electrochemical amperometry measurement system configured to bias the pair of working electrodes so that each electrode produces an amperometric signal by oxidation reaction or by reduction reaction with the electroreactive fluid or with a chemical species associated with a redox couple intended for the fluid. The microfluidic electrochemical device determines the volume flow rate of the fluid in the microfluidic channel, notably based on the inter-electrode distance and a time delay between the amperometric signals produced by the pair of working electrodes.

A microfluidic electrochemical device has a microfluidic channel and an electrochemical cell having a pair of working electrodes separated by an inter-electrode distance in a flow direction of the fluid in the microfluidic channel, a counter-electrode and a reference electrode. The microfluidic electrochemical device has an electrochemical amperometry measurement system configured to bias the pair of working electrodes so that each electrode produces an amperometric signal by oxidation reaction or by reduction reaction with the electroreactive fluid or with a chemical species associated with a redox couple intended for the fluid. The microfluidic electrochemical device determines the volume flow rate of the fluid in the microfluidic channel, notably based on the inter-electrode distance and a time delay between the amperometric signals produced by the pair of working electrodes.