Integrated chemiresistor for chemical sensing

Sensor integration

At Micronit, we offer the integration of sensors, electrodes and actuators in microfluidic and MEMS systems. By incorporating these elements, the devices can perform tests autonomously and external hardware can be simplified. Thanks to sensor integration technology, measurements can be carried out on the spot, like quality checks in the food industry or DNA analysis at a crime scene.

Sensing

At Micronit, we focus on the following sensing functionalities:

  • optical sensing, using semiconductor light sensors
  • chemical sensing, using optochemical probes and chemiresistors/transistors
  • voltage/current sensing and electrical stimulation, using thin/thick film conductors
  • temperature sensing, using thermistors/thin film resistors

We can offer this technology for many different types of projects. To get you inspired, below you can find a few cases we have worked on and successfully put the integration of different types of sensors to use!

Thin film embedded electrodes

Our microfabricated chips can be made to include thin film metal layers, for instance, platinum or gold. As temperature affects the electrical resistance of a metal, these thin film resistors can act as temperature sensors. Furthermore, thin film electrodes can be used to measure the electrical impedance of electrolytes inside a device. For instance, some of our capillary electrophoresis (CE) chips are equipped with electrodes to measure the conductivity at the end of the separation channel to detect and quantify the separated analytes.

Sensing through molecular probes

Another example of sensing is the use of molecular probes as a means to measure chemical species inside microfluidic devices. One application is the use of phosphorescent materials to measure dissolved oxygen, an application particularly relevant in cell culture systems. Patches containing the probe material are manufactured on the inside surface of devices. An optical fiber mounted in the chip holder directs the excitation light to the patches and collects the phosphorescent signal for quantification.

Sensitive readout for biological assays

Modules consisting of microfluidic flow cells integrated with, e.g. optical sensors, can be used as a sensitive readout of biological assays in Point-of-Care (PoC) tests. In a collaborative project between Janssen Diagnostics, NXP Semiconductors and Micronit, a microfluidic detection module was developed by mounting a CMOS-based sensor on a microfluidic flow cell equipped with electrical traces. This device was used for beads-based biological assays and showed better sensitivity and a lower limit of detection than conventional methods. This demonstrates the potential to develop stand-alone PoC tests, which are able to detect low concentrations of biomarkers. Microfluidics and microtechnologies thus take diagnostic capabilities out of the lab and bring them into the patients’ home.

Would you like to read more about this? We have a paper about sensor integration ready for you.

Curious to find out more about our capabilities in the field of sensor integration?

On-chip functionalities

For other essential on-chip functionalities, see our pages about