Microfluidic Chip: What is Bonding process in microfluidics?

Posted By Borja Barredo / Technology Blog / Lab on a Chip, microfluidic chip, microfluidics / No hay comentarios

Microfluidic Chip using Bonding Technique

Bonding process : The sealing of the open microchannels is necessary to produce the final enclosed fluid paths, and thus a critical step in the fabrication process invariably involves bonding a caping layer to the microchannel substrate. Bond strength is a critical consideration and bond interfaces must provide suitable chemical or solvent compatibility to prevent degradation during use, without compromising dimensional control of the microchannels due to deformation during the bonding process.

Other important considerations for the bond interface include surface chemistry, optical properties, and material compatibility and homogeneity of the channel sidewalls.

Microfluidic Bonding Process

Microfluidic Bonding process is the sealing of the open microfluidic microchannels

Additional issues such as manufacturability and compatibility with off- microfluidic chip interconnects can limit the selection of bonding methods.
Microfluidics bonding techniques may be categorized as either indirect or direct. Indirect bonding involves the use of an adhesive layer to seal two substrates and encapsulate microchannels fabricated in one or both of the substrates. In contrast, direct bonding methods fix the two substrates without any additional materials added to the interface.
While in direct bonding the bulk polymer itself comprises the adhesive giving a as a result microchannels with homogeneous sidewalls, indirect bonding methods require an intermediate adhesive that results in channel sidewalls with different chemical, optical and mechanical properties than the bulk polymer.
In general, bonding forces between mating surfaces arise from either molecular entanglement or charge interactions. Entanglement can occur by mechanical interlocking of diffusion between surfaces, while bonding due to charge interactions can result from electrostatic or chemical (covalent) bonding, acid-base interactions, or van der Waals forces.

Thermoplastic bonding methods like thermal fusion bonding, solvent bonding, localized welding and surface treatment and modification bonding are mainly achieved by molecular entanglement.

Adhesive bonding is achieved from charge interactions. In most cases bonding at high temperatures can greatly enhance polymer entanglement and interaction at the bonding interface resulting in high bong strength. However, bonding methods for microfluidic chips must be adapted and optimized for the task of enclosing micron-scale fluidic channels without excessive deformation of the channel cross sections.

Sealing injected pieces, both flat and structured pieces, is one of our well-established fabrication procedures. Alignment accuracy is around units of microns and the bonding yield reaches the 97% of the total area.

We are sealing polymers such as COC, COP, PMMA, PET and also PS, PC, but we are able to create a bonding setup for any polymer needed, doing short series or mass production.

This setup enables:

1. Accurate Flatness (Deformation ± 1 micron)

2. Ideal products for optical applications

3. Impurities-free product, done in clean room


Read More

Microfluidic Manufacturing Technique: What is Hot Embossing?

Posted By Borja Barredo / Technology Blog / Lab on a Chip, microfluidic chip, microfluidics / No hay comentarios

Microfluidic Manufacturing Technique:  Hot Embossing for Microfluidics

Hot Embossing technique used in microfluidics is a prototype and production method for creating microfluidic structures.

The first step is to create the SU8 mold of the structures you want to stamp in the polymer chip. The resolution you want to get is based on the mould, so the mask to choose is a key element. Resolutions of structures under 10 micron, a chromium mask is needed.

Microfluidic Structures to be replicated

Microfluidic Structures to be replicated


Once the mold is defined and manufacture, the hot embossing process starts. The temperature to reach is very important here. The objective is to get  a certain temperature in the process, where the material (a polymer) reaches the glass transition temperature(called Tg and is different for each polymer)

At this temperature the polymer is very “malleable”, so you can set and replicate the SU8 structures of the mould in the polymer.

Once you cool the material above the Tg Temperature it becomes hard and is alike the glass.

With this technique you are able to replicate complicated microfluidic structures in the different materials(polymers) we use, and create different designs/ microfluidic chip from one mold.





Read More

Microfluidic Applications: What is Lab on a Chip?

Posted By Borja Barredo / Technology Blog / Lab on a Chip, microfluidic companies, microfluidics / No hay comentarios

Microfluidic Chip: Lab on a chip solution

Microfluidic Lab on a Chip (LOC) is a Device which integrates one or several laboratory functions on a single chip of only milimeters to few centimeters in size and that are capable of handling extremely small fluid volumes down to less than pico liters.



The main ADVANTAGES are:

– Low fluid volume consumption

– Faster analysis and response times

– Better controlled reactions

– Optimized heat and mass transfer

– Compactness

– Low fabrication costs

There is an  increasing interest in MEDICINE , BIOLOGY and ANALYTICAL CHEMISTRY to develop these devices due to the flexibility, cost and speed.



Read More

Microfluidic Manufacturing technologies

Posted By Borja Barredo / Technology Blog / Lab on a Chip, microfluidic chip, microfluidics / No hay comentarios

Microfluidic Chips Manufacturing Technologies

microLIQUID uses several technologies for the fabrication of microfluidic structures in prototypes and serial production of microfluidic flexible chips.

For Microfluidic structures

Hot Embossing.
Etching (Wet and dry).
Breaking and Dicing.
Bonding (thermal and anodic), we bond any polymer or substrate.
Flexible chips.

For Serial production

Injection molding.

CNC Micromachining.

For Integrated electrodes

  • Metal deposition via sputtering.
  • Metal deposition via vaporization.

For Chip holders:  microfluidic connectors

Injection molding.
CNC Micromachining.

Read More

Microfluidics: What is the correct material?

Posted By Borja Barredo / Technology Blog / Lab on a Chip, microfluidic chip, microfluidics / No hay comentarios

Microfluidics Applications: Materials for different utilization

In microLIQUID we mainly use polymer materials in our product development and also glass and metals. We use them to fabricate microfluidic chips,different architectures,Integrate electrodes on microfluidic structures and Connectors (Microfluidic Chip holders).

Microfluidic structures

  • SU-8:Very precise and a good solution for prototypes.
  • COP or COC: Very good characteristics for health applications.
  • PMMA or Plexiglass clean room microfluidics.
  • PC: polycarbonate.
  • PDMS: Polydimethylsiloxane.
  • Substrates of Glass, silicon or your own processed wafers.

Integrate electrodes on microfluidic structures

  • Gold.
  • Platinum.
  • Titanium.
  • Chromium.
  • Copper.
  • Aluminium.
  • Nickel.

microLIQUID integrates metallic structures on SU8, COP, COC, PDMS, silicon and glass.

Connectors (Chip holders)

  • Plastic.
  • Metal.

The connectors have electrical connexion via Standard PCB(Printed circuit Boards).

Read More

microLIQUID joins Food for Life-Spain Technological Platform

Posted By Borja Barredo / News / Lab on a Chip, microfluidics, microLIQUID / No hay comentarios

MicroLIQUID has reached an agreement to join the technology platform FOOD FOR LIFE – Spain(PTF4LS), working on the development of detection systems in Food & Health, along with Food Security.

Food for Life- Spain logo

Food for Life- Spain

Technology Platforms like this, are a group of stakeholders in a particular sector, led by industry, with the aim of defining a Strategic Research Agenda (acronym: SRA) on important issues and great social relevance, in which achieve European objectives of growth, competitiveness and sustainability depend on technological advances and research in the medium and long term.

Technology Platforms are based on the definition of a Strategic Research Agenda and mobilizing the critical mass of research and innovation effort needed.
Guide research in supply to industrial interests and the interests of society. The aim of this platform is to reach a consensus among all (companies and researchers) on issues of interest to be investigated. This consensus will materialize in the development of a Strategic Research Agenda.

The intention is that projects to be submitted to the various national R & D + Innovation plans are made based on the needs of the sector and not just those of the research centers or other stakeholders only.

microLIQUID joins in the project based on the capacity of the company of generating new detection systems in the Food & Health sector, like the example we see in the picture

point of care and detection systems based in microfluidics

microLIQUID develops and manufactures  new detection systems based in microfluidics in the Food & Health sector





Read More

Microfluidic Probes: EPILEPSY Research in HUMAN awarded by FIPSE

Posted By Borja Barredo / News / epilepsy, idival, Lab on a Chip, microfluidics, neuron, Neuroscience, parkinson / No hay comentarios

Microfluidic Probes for EPILEPSY Research

Microfluidic microprobes to record neuronal activity and local application of drugs, to be applied to the electrophysiological monitoring or pre-surgical intra-operative of adult patients with refractory epilepsy, awarded with the FIPSE Project in Phase 1.

fprobes - microfluidic microprobes for epilepsy research

fprobes – microfluidic microprobes for epilepsy research


This project, coordinated by the Department of Neurophysiology at the Hospital Marqués de Valdecilla-Valdecilla Health Research Institute (IDIVAL) (Dr. José Luis Fernández Torre), integrates researchers from the CSIC Cajal Institute in Madrid (Dr. Liset Menendez de la Prida ) and the  microLIQUID in Basque Country (Dr. Ane Altuna), a multidisciplinary team with a long research career in their respective fields of expertise.

Dr. José Luis Fernández Torre is the principal investigator of this project, is Head of Clinical Neurophysiology, University Hospital Marqués de Valdecilla, Vice president of the National Committee for Clinical Neurophysiology, Associate Professor in the Department of Physiology and Pharmacology, Faculty of Medicine Santander (UNICAN) and creator and in charge  of the Research group  for clinical research associate of Neurophysiology in Epilepsy and Neurointensives in the Valdecilla Research Institute (IDIVAL). He has published over 80 articles in prestigious journals such as Clinical Neurophysiology, Epilepsy, Neurology and Journal Neurology, Neurosurgery and Psyschiatry.

Liset Menendez de la Prida is doctor in Neuroscience (1998) in the program of the prestigious Institute of Neurosciences of Alicante, is an international expert in the study of the neural mechanisms of high frequency oscillations (or HFOs) in epilepsy. She has participated in numerous international projects of the European Commission and prestigious institutions such as the Human Frontier Science Program, and published in the top journals in the field as Neuron and Nature Neuroscience. It has 5 accredited six-year research periods for her scientific activity, she has directed four doctoral theses and has 2 ongoing, and regularly participates as a speaker at the prestigious Gordon Conference on Epilepsy and guest in prestigious foreign institutions.

Ane Altuna is doctor by the University of the Basque Country (2012), currently head of R & D in Microliquid, she developed her career in science and technology in IKERLAN where she designed and finalized the production of integrated electrical probes for brain recording. Expert in SU-8, biocompatible polymer that makes up the structural material of our integrated probes, has published her work in the most prestigious journals in the field, such as Lab-on-chip or Biosensors and Bioelectronics.


microfluidic microprobes for Epilepsy Research

microfluidic microprobes – Epilepsy


The aim of the project is to assess the feasibility of integrated microscopic probes (<150 microns diameter) aimed to record neuronal activity and to deliver drugs locally for preoperative or intraoperative electrophysiological monitoring of adult patients with refractory epilepsy evaluated for surgery or and neurocritical patients (in coma) with spontaneous intracerebral hemorrhage, subarachnoid hemorrhage, malignant stroke and severe head trauma during continuous multimodal monitoring. With this project they intend to evaluate: a) the clinical opportunity for intracranial integrated recordings and local drug delivery solutions; b) the technical adjustments required to bring current experimental prototypes to pre-clinical tests; c) the activities of both basic and clinical research necessary to bring our technology to the field of clinical intracranial monitoring.

Most of the probes used in the clinic for recording EEG and ECoG are the macroelectrodes type, with dimensions ranging from a few tens of microns (> 500 microns) to a few millimeters (1-2 mm). The use of such electrodes has played a key role in the development of new functional therapies used successfully in the treatment of various neurological diseases such as Parkinson‘s disease, Epilepsy or chronic intractable pain.

microfluidic microprobes detail for Epilepsy Research

microfluidic microprobes detail for Epilepsy Research

The project proposes the design of cutting-edge biomedical technologies focused on the development of fProbes, integrated probes for neural recording and delivery of drugs in local, currently marketed by microLIQUID in the field of basic neuroscience. It is planned to evaluate the clinical and technical aspects associated with its implementation as a solution to the problem of intracranial clinical monitoring of refractory epilepsy and intracerebral hemorrhage, stroke and traumatic brain injury.

fProbes is the trademark under which microLIQUID is currently marketing our integrated fluidic solutions for neural recording and drug delivery in local in the field of neuroscience

Read More

where are we?