The simultaneous application of interlaced innocuous warm and cool stimuli can elicit sensations of burning heat (the Thermal Grill Illusion, TGI). The TGI is thought to reflect changes in the central interactions between somatosensory sub-modalities (i.e. cold-inhibition of pain). Previous studies used multiple alternating warm and cool bars to elicit a TGI. The primary objective of this study was to evaluate the effects of altering the placements of warm and cool grill elements on the intensities of perceived pain and unpleasantness in 26 male subjects. Arranging the thermal grill elements in a warm flanking cool (WCW) pattern evoked significantly higher intensities of pain and unpleasantness than a cool flanking warm (CWC) pattern and a uniform warm stimulus. Conversely, CWC did not elicit significantly different intensities of perceived pain and unpleasantness than a uniform cool stimulus. This finding may reflect differences in the level of activation of central neurons.

The simultaneous application of interlaced innocuous warm and cool stimuli can elicit sensations of burning heat (the Thermal Grill Illusion, TGI). The TGI is thought to reflect changes in the central interactions between somatosensory sub-modalities (i.e. cold-inhibition of pain). Previous studies used multiple alternating warm and cool bars to elicit a TGI. The primary objective of this study was to evaluate the effects of altering the placements of warm and cool grill elements on the intensities of perceived pain and unpleasantness in 26 male subjects. Arranging the thermal grill elements in a warm flanking cool (WCW) pattern evoked significantly higher intensities of pain and unpleasantness than a cool flanking warm (CWC) pattern and a uniform warm stimulus. Conversely, CWC did not elicit significantly different intensities of perceived pain and unpleasantness than a uniform cool stimulus. This finding may reflect differences in the level of activation of central neurons.

Micro-scale self assembly is an attractive method for manufacturing sub-millimeter sized thermoelectric device parts. Challenges controlling assembly yield rates, however, have caused research to find novel ways to implement the process while still resulting in a working device. While a typical system uses single n-type and p-type material elements in series, one method used to increase the probability of a working device involves adding redundant parallel elements in clusters. The drawback to this technique is that thermal performance is affected in clusters which have missing elements. While one-dimensional modeling sufficiently describes overall performance in terms of average junction temperatures and net heat flux, it fails when a detailed thermal profile is needed for a non-homogeneous system. For this reason, a three-dimensional model was created to describe thermal performance using Ansys v12.1. From the results, local and net performance can be described to help in designing an acceptable self-assembled device. In addition, a haptic thermal display was designed using thermoelectric elements with the intention of testing the thermal grill illusion. The display consists of 5 electrically independent rows of thermoelectric elements which are controlled using pulse width modulating direct current motor controllers.