**Preface to "Lab-on-PCB Devices"**

Lab-on-PCB (LoP) has been the subject of increasing research in recent years. These kinds of devices emerge as an interesting evolution of "lab on a chip" and "PCB-MEMS". They share many properties with lab-on-chip devices and microfluidics, namely, rapid response time and small fluid volume for samples and reagents. In addition, lab-on-PCB is especially interesting due to the integration of electronics, microfluidics, sensors and actuators in a single platform. Beyond this integration, the interest lies in the commercial availability of the Printed Circuit Boards with reasonable dimensions and tolerances at low cost. This fact makes LoP devices an attractive option from the market point of view. However, lab-on-PCB is far from being a robust technology. Unlike electronic microchips, the development of LoP devices covers many fields (electronics, materials, biology, medicine, fluid mechanics, etc.) and therefore they require a highly multidisciplinary R&D group. In addition, they are lacking in standardization for both design and end-user interfaces. Futhermore, the core of LoP devices is based on the integration of sensors, biosensors and actuators. The actuators are intended to move the samples through the LoP device, and for conditioning the samples, for example using integrated microheaters.

This work is addressed to researchers interested in developing mass-produced biomedical devices and microdevices. In addition, this is a good guide for beginners to learn about Lab-on-PCB devices and PCB-MEMS thanks to the review papers and the rest of the contributions as current interesting examples.

I would like to thank all the authors for submitting their papers to the Special Issue "Lab on PCB Devices". I also thank all the reviewers, editors and the MDPI staff for taking their time to improve the quality of the papers.

> **Francisco Perdigones** *Editor*
