Abstract: A microfluidic valve assembly and a microfluidic sensing platform are provided. The valve assembly has particular utility for separating test fluids from being in contact with a soft substrate, for example, a PDMS substrate. The valve member includes a stretchable membrane positioned to seal a fluid channel. The microfluidic sensing platform is particularly suited for detecting and/or quantifying the presence of one or more target agents in a fluid sample. This system includes a microfluidic chip configured to receive a capture agent and detection agent; a controller configured to control flow of a capture agent and a detection agent; and a sensor configured to detect results of the interaction between the target agents and the mixture of the capture agent and the detection agent.

Abstract: A microfluidic valve assembly and a microfluidic sensing platform are provided. The valve assembly has particular utility for separating test fluids from being in contact with a soft substrate, for example, a PDMS substrate. The valve member includes a stretchable membrane positioned to seal a fluid channel. The microfluidic sensing platform is particularly suited for detecting and/or quantifying the presence of one or more target agents in a fluid sample. This system includes a microfluidic chip configured to receive a capture agent and detection agent; a controller configured to control flow of a capture agent and a detection agent; and a sensor configured to detect results of the interaction between the target agents and the mixture of the capture agent and the detection agent.

Abstract: Provided is a method for measurement of a change in environment at a sensor. The sensor has: a first layer formed of a piezoelectric material; a second layer formed adjacent the first layer and acoustically coupled with the first layer; and electrodes disposed to apply a driving signal to the first layer to generate bulk acoustic waves. The temperature coefficient of frequency of the first layer is different to that of the second layer. In the method, a first layer resonant frequency associated with the first layer and a combination resonant frequency associated with a combination of the first and second layers are detected. A shift in one or both of the first layer resonant frequency and the combination resonant frequency is detected. A portion of the shift caused by a temperature change at the sensor is identified. Another portion of the shift caused by an environmental change at the sensor other than the temperature change is identified.

Abstract: Provided is a method for measurement of a change in environment at a sensor. The sensor has: a first layer formed of a piezoelectric material; a second layer formed adjacent the first layer and acoustically coupled with the first layer; and electrodes disposed to apply a driving signal to the first layer to generate bulk acoustic waves. The temperature coefficient of frequency of the first layer is different to that of the second layer. In the method, a first layer resonant frequency associated with the first layer and a combination resonant frequency associated with a combination of the first and second layers are detected. A shift in one or both of the first layer resonant frequency and the combination resonant frequency is detected. A portion of the shift caused by a temperature change at the sensor is identified. Another portion of the shift caused by an environmental change at the sensor other than the temperature change is identified.

Abstract: An ultrasonic transducer array and method of making an ultrasonic transducer array. The array comprising a plurality of individual array elements made from a piezoelectric composite which is made from a plurality of individual piezoelectric segments; a passive filler between the piezoelectric segments; and, one or more electrodes for driving the array elements formed from the piezoelectric segments; wherein the spatial pattern of the piezoelectric segments of the piezoelectric composite defines one or more non-linear, irregular channels which separate the piezoelectric segments thereby minimising interaction between the individual array elements and minimising spurious modes in the ultrasound transducer array.