A stiffness controllable multimodal whisker sensor follicle for texture comparison

Mammals like rats, who live in dark burrows, heav-ily depend on tactile perception obtained through the vibrissalsystem to move through gaps and to discriminate textures. Theorganization of a mammalian whisker follicle contains multiplesensory receptors and glands strategically organized to capturetactile sensory stimuli of different frequencies. In this paper, weused a controllable stiffness soft robotic follicle to test the hy-pothesis that the multimodal sensory receptors together with thecontrollable stiffness tissues in the whisker follicle form a physicalstructure to maximize tactile information. In our design, the ringsinus and ringwulst of a biological follicle are represented by alinear actuator connected to a stiffness controllable mechanismin-between two different frequency-dependent data capturingmodules. In this paper, we show for the first time the effectof the interplay between the stiffness and the speed of whiskingon maximizing a difference metric for texture classification

A stiffness controllable multimodal whisker sensor follicle for texture comparison

Mammals like rats, who live in dark burrows, heavily depend on tactile perception obtained through the vibrissal system to move through gaps and to discriminate textures. The organization of a mammalian whisker follicle contains multiple sensory receptors and glands strategically organized to capture tactile sensory stimuli of different frequencies. In this paper, we used a controllable stiffness soft robotic follicle to test the hypothesis that the multimodal sensory receptors together with the controllable stiffness tissues in the whisker follicle form a physical structure to maximize tactile information. In our design, the ring sinus and ringwulst of a biological follicle are represented by a linear actuator connected to a stiffness controllable mechanism in-between two different frequency-dependent data capturing modules. In this paper, we show for the first time the effect of the interplay between the stiffness and the speed of whisking on maximizing a difference metric for texture classification

Preliminary study on Lampyrids in Kiralakelle nature reserve, Matara District, Southern Sri Lanka; An ecotourism perspective

Lampyrids  or fireflies are one of the ecotourism subjects throughout the world and there is a possibility to use them as a rapidly increasing tourism aspect in Sri Lanka. Previous records have revealed 63 species of fireflies belonging to 24 genera were listed in the country. However, the ecotourism significance of Sri Lankan firefly fauna is poorly studied and never been documented. The aim of the present study was to introduce the existing lampyrid fauna of Kiralakelle nature reserve in ecotourism view point as one of proposed tourism development site in Southern Province, Matara, Sri Lanka.Study carried out throughout year 2010 from 6.00 p.m. to 22.00 p.m. as one sampling in each month. Fireflies were observed using 6 observation points located in two types of landscapes (1-3 points closer to forest patches and 4-6 closer to marshy water filling lands) along the main pathway of the nature reserve. Each point had 2.5 m radius and distance between two points was 250m. Abundance and diversity indices were estimated. Totally, 7 adult firefly species, namely  Luciola cingulata,  L. extricans,  L. melaspis,  L. praeusta  complex, and Asymmetricata humeralis,  Curtos costipennis  and  Lamprigera tenebrosa  were recorded. Genus-  Luciola  was the dominant lampyrid group in nature reserve and the lowest abundance was recorded in genus-Lamprigera  fireflies. While  A. humeralis  was the highly abundant species in nature reserve,  L. extricanswas recorded as the less abundant one. The highest percentage abundance of recorded lampyrids was shown in observation point 1 and the lowest in point 5. The average percentage abundance of lampyrids was high in 1-3 observation points closer to forest patches than others.  L. cingulata, L. praeusta  complex and  A. humeralis were shown their abundance throughout the year in Kiralakelle nature reserve and the other 4 species were recorded as seasonally dominant lampyrids. The highest Shannon Wiener diversity was obtained from observation point 2 (1.554) and the lowest in point 6 (1.240). Records of this  study will be helpful for better understanding of firefly fauna in Kiralakelle nature reserve and provide clear outline of their usability for tourism success. The site  currently has threatened by illegal human activities such as felling, garbage filling,  animal hunting and forests firing. Hence, additional conservation strategies are needed to protect the lampyrid fauna in this nature reserve. Sustainable ecotourism based on lampyrids will be a vital aspect to succeed the night-tourism industry in Kiralakelle nature reserve in future and throughout Sri Lanka as well.Key words: Ecotourism, Kiralakelle nature reserve, Lampyrid

A biologically inspired multimodal whisker follicle

Mammalian whisker follicle contains multiple sensory receptors strategically organized to capture tactile sensory stimuli of different frequencies via the vibrissal system. There have been a number of attempts to develop robotic whiskers to perform texture classification tasks in the recent past. Inspired by the features of biological whisker follicle, in this paper we design and use a novel soft whisker follicle comprising of two different frequency-dependent data capturing modules to derive deeper insights into the biological basis of tactile perception in the mammalian whisker follicle. In our design, the innervations at the Outer Conical Body (OCB) of a biological follicle are realized by a piezoelectric transducer for capturing high frequency components; whereas the innervations around the hair Papilla are represented by a hall sensor to capture low frequency components during the interaction with the environment. In this paper, we show how low dimensional information such as the principle components of co-variation of these two sensory modalities vary for different speeds and indentations of brushing the whisker against a surface. These new insights into the biological basis of tactile perception using whiskers provides new design guidelines to develop efficient robotic whiskers

A method to guide local physical adaptations in a robot based on phase portraits

In this paper, we propose a method that shows how phase portraits rendered by a controller can inform the development of a physical adaptation at a single degree of freedom (DoF) for a given control task. This approach has the advantage of having physical adaptations sharing the responsibility of control to accomplish a task. We use an inverted pendulum which is reminiscent of the trunk of a biped walker to conduct numerical simulations and hardware experiments to show how our method can innovate a physical adaptation at the pivot joint to reduce the control effort. Our method discovered that a torsional spring at the pivot joint would lead to a lower input effort by the regulator type feedback controller. The method can tune the spring to minimize the total cost of control up to about 32.81%. This physical adaptation framework allows multiple degrees of freedom robotic system to suggest local physical adaptations to accomplish a given control objective

Socio-Demographic profile of Cutaneous Leishmaniasis patients in Hambantota District, Sri Lanka

Cutaneous leishmaniasis (CL) is known to Sri Lanka from 1992. The distribution of the disease is increasing and large numbers of CL cases are reported from Hambantota district. This study was focused on selected clinical features and socio-demographic factors of CL positive patients in Hambantota district and this information were collected using a questionnaire from CL suspected patients who attended to the Tangalle Hospital from June, 2016 to January, 2017. For selecting the CL positivity, slit skin smears were obtained from lesions of suspected patients. These smears were stained and examined for Leishmania amastigotes. Smears were positive in 183 patients. Majority of them had one lesion on the body and 117 patients were males (p<0.001). The most affected age group was >50 years. House-wives and students were identified as highly affected occupants. The higher number of CL patients lived in rural areas (p<0.001). Most of the CL patients lived in houses with cemented floors and walls with tiled -roofs meanwhile 117 houses had cracks, either in floors or walls. Further, 95.5% of patients were unaware of sand-fly biting. These findings highlight the socio-demographic profile of the CL patients in Hambantota district which will be important for the disease management strategies