Lukas Matter, Electronics Materials and Systems Laboratory

Discussion leader: Julie Gold, Professor at Nano and Biophysics, Chalmers
Supervisor: Maria Asplund, Professor at Electronics Material and Systems, Chalmers
Co-Supervisor: Darren Svirskis, Professor in the School of Pharmacy, University of Auckland, New Zealand
Examiner: Dag Winkler, Professor at Quantum Device Physics, Chalmers
Director of Studies: Per Lundgren, Professor at Electronics Material and Systems, Chalmers

Abstract:
Spinal cord injury (SCI) distorts the communication between the brain and the body typically causing long-term neurological impairments such as the permanent loss of motor function and sensation below the level of the injury. Electrical stimulation (ES) shows promise as a therapy to promote recovery and regeneration after SCI. Two applications of ES to treat SCI are commonly distinguished. Bursts of short pulses in the range of μs are delivered to the intact neural circuits below the level of injury to restore functions through neuromodulation. In contrast, sustained electrical fields with pulses in the range of seconds to minutes aim to promote the regenerative process itself and thus cause long-lasting improvements.
In general, ES of tissue is challenging because the stimulation can cause the generation of toxic stimulation by-products. Additionally, for spinal cord stimulation, electrodes need to be brought in contact with the cord, which requires conformable implants to avoid compression. We leveraged new possibilities in bioelectronics such as thin-film polyimide implants, and supercapacitive, stable electrode materials, to develop implants for neuromodulation and sustained field therapy after SCI.
In this midway seminar the various engineering approaches available to generate sustained electric fields in the spinal cord are discussed and an overview of existing studies in the field is given. The tissue-electrode interface is highlighted by a comparison of the generation of stimulation by-products from sputtered iridiumoxide films, laser-induced graphene, and the conducting polymer poly(3,4-ethylenedioxythiophene). Additionally, our own approaches to implants developed for neuromodulation in a pig SCI model, and neuroregeneration in a rat SCI model are shown and first rat treatment results are discussed.