Biomedical Engineering

Biomedical Microsystems

Microsensors & Microfluidics

• Biohybrid technology
  - bioimpedance spectroscopy (in vitro and in vivo)
  - sensor systems for medical in vivo diagnostics
  - technologies for the non-destructive characterization, processing and handling of individual cells
  - miniaturized incubation chamber with integrated real-time video monitoring for cell culture
• Microfluidics and biocell handling systems
  - microfluidic systems as a fluidic interface to biosensors and biochips
  - micro-injection chips for cell injections (needle and pump on a microchip)
• Microsensors and microactuators
  - mass flow sensors with integrated conductivity measurement
  - sensors for the measurement of film thicknesses (e. g. thickness of a film of saliva in the oral cavity)
  - miniaturized systems, as applicable with wireless actuation/data acquisition
• Assembly and packaging technology
  - packaging of bioanalysis chips and microimplants
  - design and production of ultrathin (5-10 µm), flexible printed circuit boards with conductor width > 5 µm
  - hybrid-integrated film technologies (thick film, thin film technology) 
• Thin-film technology
  - deposition of low-stress silicon-nitride films (PECVD)
  - deposition of water-impermeable parylene films
  - deposition of metallic and dielectric films (sputtering)
• Microstructuring
  - 3D rapid prototyping of SU-8 photo resist using femtosecond laser (structural resolution: 300 nm)
  - photolithography
  - wet chemical etching
  - dry etching (RIE) of parylene C and polyimide, silicon nitride and silicon dioxide
• Replication technologies
  - silicone moulding
  - rotative hot embossing of (fluidic) microstructures in large-area, continuous polymer films
  

Biotelemetry

• wireless telemetry systems for
  - the assessment of physiological and technical signals/parameters
  - biomonitoring

• control of medical implants
  
• use of various technologies
  - inductive (RFID technology)
  - optical, also transcutaneous IR transmission
  - wireless (Bluetooth)
• development of size-optimized sensor, actuator and communications technology
• development of electronics especially for biomedical implants
• optimization of coil geometries for the simultaneous wireless communication, data and energy transmission
• development of antennae for data transmission (MICS band)
  

Active Implants

• conception, design, development and prototyping of active implant systems 
• application examples in dental and orthopaedic technology, in electrostimulation and sensor technology
• design and electronic development (hardware and firmware/software) in cooperation with the working groups Biotelemetry and Microsensors & Microfluidics
• efficient powering of and secure communication with implants
  
• encapsulation of active implants (rigid and flexible)
• in vitro testing of biocompatibility and biostability
  
• application of mature and development of new technologies and methods
• testing in house and in cooperation with certified test houses
• technical documentation and risk management
• cooperation with certified medical technology manufacturers and service providers
• Application examples and competences
  - dental implant to stimulate saliva production
  - dental implant to administer medication via the oral mucosa
  - long-term implantable intracranial pressure sensor
  - shunt system for hydrocephalus therapy
  - active implant for the therapy and rehabilitation of spine disorders
  - wireless control of an implant for electrostimulation of nerves/muscles

Biomedical Engineering & Neuroprosthetics

Technology

• customer-specific design, manufacturing and characterization of flexible, implantable polyimide microelectrodes in a wide range of construction forms (e. g. cuff, shaft, sieve, thread, array) and application (e. g. peripheral nerve, ECoG, retina, vestibularis, musculature)
  
• coating of the electrode surface to reduce impedance and increase the reversible charge injection capacity
  
• evaluation of the long-term reliability of implants (encapsulation materials, electrode layers and supply lines)
  
• hybrid assembly and encapsulation of biomedical microimplants
  
• mask design for 2D and 3D microelectrodes
  
• manufacturing of microimplants with integrated electronics
  
• development of dry surface electrodes including material tests and investigations of the transmission behaviour
  
• design and manufacturing of recording and stimulation circuits
  
• encapsulation of random structures and geometries with parylene
  
• rapid prototyping (3D printer, 3D scanner)
  
• development and manufacturing of autonomous, distributed sensors and actuators

Methodology

• development of customer-specific measurement stations for the verification of the long-term stability of implantable structures
  
• eye-tracking for usability tests and reading behaviour (high-speed and helmet-based system)
  
• registration and analysis of eye movements, vision path and fixation duration for different applications (e. g. while driving vehicles, advertising, design etc.)
  
• development of methods and equipment for clinical neurophysiology and psychology including new methods of signal analysis such as online beat-to-beat determination of the pulse transit time, heart rate variability etc.
  
• system design of neuroprostheses
  
• thermography in the case of technical and biological issues
  
• vigilance investigations and registration of emotions in the drive simulator
  
• examination of implant materials under physiological conditions and accelerated aging
  
• development of stimulation patterns, recording systems, material tests
  
• characterization of microelectrodes, material properties of surface electrodes, long-term behaviour of surface electrodes

Consulting

• consulting on biocompatible coating and encapsulation materials (polyimide, parylene, silicone) and organic electrode material
• technical assistance for electrophysiological measurements in vitro, in vivo and human
• investigations on functional electrostimulation and neuromodulation at peripheral nerves
• implant technology and elaboration of implantation tools for microimplants
• risk management, quality assurance and verification of the biocompatibility and long-term stability
• preparation and monitoring of clinical studies