Photo-controlled bio-mimicking dry adhesive

The goal of this work is to develop a photo-switchable dry adhesive. Spiropyran doped PDMS polymer was moulded into biomimetic mushroom-shaped fibrillar adhesive microstructures characterized using a variety of measurement techniques and compared with a flat control surface made of the same material. Using UV light to generate of charged merocyanine molecules within ‘mushroom’-shaped micro-structured PDMS films enhanced the adhesion of the film to glass surfaces. The strength of the dry adhesive property can be lowered back to the original state using visible light. Quick and efficient switching in the polymer was observed. Integrating this molecule increased normal adhesion of unstructured samples by a factor of ~4 when polymer was in the neutral spiropyran form and ~5 for the merocyanine zwitterionic isomer, which demonstrated that control over the adhesion strength was possible. Surface charge and contact angle measurements further confirmed the proper functionality of the switch inside the PDMS polymer

A Photoresponsive Biomimetic Dry Adhesive Based on Doped PDMS Microstructures

A Photoresponsive Biomimetic Dry Adhesive Based on Doped PDMS Microstructure

Integrated optical temporal Fourier transformer based on a chirped Bragg grating waveguide

We experimentally demonstrate the first integrated temporal Fourier transformer based on a linearly chirped Bragg grating waveguide written in silica glass with a femtosecond laser. The operation is based on mapping the energy spectrum of the input optical signal to the output temporal waveform by making use of first-order chromatic dispersion. The device operates in reflection, has a bandwidth of 10 nm, and can be used for incident temporal waveforms as long as 20 ps. Experimental results, obtained through both temporal oscilloscope traces and Fourier transform spectral interferometry, display a successful Fourier transformation of in-phase and out-of-phase pairs of input optical pulses, and demonstrate the correct functionality of the device for both amplitude and phase of the temporal output

Portable neuromodulation induces neuroplasticity to re-activate motor function recovery from brain injury: a high-density MEG case study

Background: In a recent high-profile case study, we used functional magnetic resonance imaging (fMRI) to monitor improvements in motor function related to neuroplasticity following rehabilitation for severe traumatic brain injury (TBI). The findings demonstrated that motor function improvements can occur years beyond current established limits. The current study extends the functional imaging investigation to characterize neuromodulation effects on neuroplasticity to further push the limits. Methods: Canadian Soldier Captain (retired) Trevor Greene (TG) survived a severe open-TBI when attacked with an axe during a 2006 combat tour in Afghanistan. TG has since continued intensive daily rehabilitation to recover motor function, experiencing an extended plateau using conventional physical therapy. To overcome this plateau, we paired translingual neurostimulation (TLNS) with the continuing rehabilitation program. Results: Combining TLNS with rehabilitation resulted in demonstrable clinical improvements along with corresponding changes in movement evoked electro-encephalography (EEG) activity. High-density magneto-encephalography (MEG) characterized cortical activation changes in corresponding beta frequency range (27 Hz). MEG activation changes corresponded with reduced interhemispheric inhibition in the post-central gyri regions together with increased right superior/middle frontal activation suggesting large scale network level changes. Conclusions: The findings provide valuable insight into the potential importance of non-invasive neuromodulation to enhance neuroplasticity mechanisms for recovery beyond the perceived limits of rehabilitation.Other UBCNon UBCReviewedFacult