Category Archives: Applications

Microfluidics

Organs on a Chip

Design and Prototyping of a novel “Organs-on-a-Chip” Bioreactor System for Substance Testing

This work was conducted by
Fraunhofer IWS Dresden, TU Berlin, ProBioGen AG Berlin, GeSiM mbH

 

Introduction

The prototype of this “organs-on-a-chip” (OOC) platform is supposed to enable studies of the interaction of consumer-relevant synthetic or natural substances with the human body in its typical environments and with its individual genotypic specificities. It has been designed for the long-term culture of human sub-organoids in small cavities of a microfludic flow-through cell.

 

Design of the Multi-Bioreactor Chip

A double sided micromachined silicon chip at the size of a standard glass slide is the heart of the bioreactor. It contains the growth segments and the cavities for the stem cells. The silicon chip is than enhanced with a PDMS layer shaping fluidic structures for supply and removal of reagents.

 

Features:

- Standard microscope slide format
- Six identical micro-bioreactor systems per chip
- Common central medium reservoir
- Live tissue imaging
Each micro-bioreactor consists of

- Three ogan growth segments
- A stem cell niche cavity
- Three behavior sensors
- Three waste reservoirs
Multi Organchip

Multi Organchip

Bioreactors on the Multi-Organ-Chip

Bioreactors on the Multi-Organ-Chip

 

 

 

 

 

LayerMaterialTechnologyFunctions 
1PDMS (2000 µm)CastingChannels and reservoirs
Cross section of the Multi-Bioreactor-Chip

Cross section of the Multi-Bioreactor-Chip

2Glass (200 µm)Lithography, LaserClosing layer
3Silicon (400 µm)Lithography, LaserChannels, organ growth segments & stem cell niche
4Glass (200 µm)Sensors and heatersSensors and heaters

The micromachining department at GeSiM contributed to the development by:

  • Lithography and mask design
  • Development of a new deep RIE etching process for micro patterning of silicon wafers
  • Adaptation of the PDMS casting technology for the fluidic reservoirs (Layer 1)
  • Development of a three layer glass/silicon/glass sandwich with embedded heater/sensor arrays (Accuracy of temperature control 0.1 K)

 

Instrumentation

GeSiM developed a docking station for unattended operation of the bioreactor chip. Laboratory compatibility was ensured by sticking to the common micro titer plate format (Approx. 125 mm x 83 mm). Therefore the bioreactor docking station fits to common laboratory robots, shakers, incubators, microscope stages and others.

Features:

  • Data exchange with PC
  • Battery based operation for at least 2 hours
  • Automatic charging in the docking station
  • Data acquisition and logging for at least 14 days (E.g. temperature)
  • Monitoring and alerting function for limit values