We designed an 'intersectional short pulse' stimulation method to inject sufficiently high current intensities into the brain, while keeping the charge density and sensation on the scalp surface relatively low.
Evolution in time of Nyquist plots during the Er doping of two nominally identical PSi samples, 1.25 μm thick, carried out at high current intensities (I = +0.02 mA for a and I = +0.06 mA for b).
One of the disadvantages of substance delivery into skin by iontophoresis is the risk of shocks and burns due to the exposure of an electric current in the skin for long periods, overdose, lesions at the site of application, alternation of the pH and high current intensities [ 49, 50].
In a hard chromium electroplating process, a heat exchanger is employed to remove the heat produced from the high current intensity in an electroplating bath.
Furthermore, at most ICMS sites, we did not systematically apply high current intensity, to prevent cortical damage, and therefore the ICMS may have been sub-threshold to elicit ipsilateral distal movements.
The optimal current intensity for hydroxyl radical formation was found to be 0.4 A since at higher current intensities 0.6 A, 0.8 A and 1 A corrosion rate was of the order 0.176, 0.381 and 0.386 mm hr−1 respectively.
To reduce the scalp stimulation side effects and enable recording of brain activity during stimulation, we designed an ISP stimulation method that allowed injection of higher current intensities into the brain compared to conventional tACS and transcranial direct current stimulation (tDCS) approaches, while keeping the cumulative charge density on the scalp surface and sensation relatively low.
The nanocomposite, N-FLG@poly[1], prepared by in situ electropolymerization, showed similar electrochemical responses to pristine poly[1], but with more well-defined redox peaks and higher current intensities, in compliance with larger electroactive surface coverage.
Even if the Er% for this sample is below the quantitative threshold, the SEM-EDS measurements demonstrate that the total amount of Er deposited is significantly different for lower and higher current intensities despite the transferred charge and the PSi parameters being identical: lower currents lead to lower doping levels.
Higher current intensities and more frequent resuspension events occur on the upper and lower slope than on the middle slope [75], thus the finest-textured sediments are found on middle slope (∼1250 m) while coarser sediments are found on the upper (250 and 550 m) and lower (2100 m) slope [26].
If the pulses are short, higher current intensities are required to make the neuron fire, and the first action potential is fired with a shorter delay after the pulse onset.
