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1. Aye-aye’s middle finger kinematic modeling during tap-scanning

   https://doi.org/10.1117/12.2612943  

   Kang, Jiming; Nemati, Hamidreza; Dehghan-Niri, Ehsan (April 2022, SPIE, Smart Structures/NDE, 300 Long Beach Blvd, Long Beach, CA, 2022)

   Lakhtakia, Akhlesh; Martín-Palma, Raúl J.; Knez, Mato (Ed.)

   The aye-aye (Daubentonia madagascariensis) is a nocturnal lemur native to the island of Madagascar with a special thin middle finger. The aye-aye’s third digit (the slenderest one) has a remarkably specific adaptation, allowing it to perform tap-scanning (Finger tapping) to locate small cavities beneath tree bark and extract woodboring larvae from it. This finger, as an exceptional active acoustic actuator, makes an aye-aye’s biological system an attractive model for Nondestructive Evaluation (NDE) methods and robotic systems. Despite the important aspects of the topic in engineering sensory and NDE, little is known about the mechanism and movement of this unique finger. In this paper a simplified kinematic model was proposed to simulate the aye-aye’s middle finger motion. 

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2. Pioneering a biomimetic approach for the acoustic near-field measurement of aye-aye biological auditory system

   https://doi.org/10.1117/12.2613158  

   Nemati, Hamidreza; Dehghan-Niri, Ehsan (April 2022, SPIE, Smart Structures/NDE, 300 Long Beach Blvd, Long Beach, CA, 2022)

   Lakhtakia, Akhlesh; Martín-Palma, Raúl J.; Knez, Mato (Ed.)

   The aye-aye (Daubentonia madagascariensis) is the largest nocturnal primate in the world and possesses a number of distinct adaptations. The most striking feature of the aye-aye is perhaps its exceptional near-field auditory system adopted to support its unique tap-scanning process. This tap-scanning technique represents prominent evolutionary innovations in the animal’s biological auditory system. The current study provides an initial insight into proposing a biomimetic approach to determine how different morphological features might impact the ayeaye’s acoustic near-field auditory system. The experimental setup comprised a miniature piezoelectric hammer mounted on a Universal Robotics manipulator (UR5) (the integrated system provides a controlled tapping process) and a prepolarized capacitive measurement microphone (to capture the acoustic sound coming from each tap on the wooden sample). The pinnae of the aye-aye were 3D printed using a CT scan obtained from a carcass. The results show that the biomimetic setup can successfully be used for evaluating the near-field auditory system of aye-ayes. 

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3. Enhancing biomimetic design of tap scanning sensors through high-resolution thermal camera-based behavioral studies

   https://doi.org/10.1117/12.3027268  

   Masurkar, Nihar; Nemati, Hamidreza; Dehghan_Niri, Ehsan (May 2024, SPIE)

   Lakhtakia, Akhlesh; Martín-Palma, Raúl J; Knez, Mato (Ed.)

   Researchers conventionally employ thermal imaging to monitor the health of animals, observe their habitat utilization, and track their activity patterns. These non-invasive methods can generate detailed images and offer valuable insights into behavior, movements, and environmental interactions. The aye-aye (Daubentonia madagascariensis), a rare and endangered lemur from Madagascar, possesses a uniquely slender third finger evolved for tapping surfaces at relatively high frequencies. The adaptation enables acoustic-based sensing to locate cavities with prey in trees to enhance their foraging abilities. The authors’ previous studies have demonstrated some descent simulating dynamic models of the aye-aye’s third digit referenced from limited data collected with monocular cameras, which can be challenging due to noisy and distorted images, impacting motion analysis adversely. In this proposed research, high-speed thermal cameras are employed to capture detailed finger position and orientation, providing a clearer understanding of the overall dynamic range. The improved biomimetic model aims to enhance tap-testing strategies in nondestructive evaluation for various inspection applications. 

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4. Unprecedented female mutation bias in the aye-aye, a highly unusual lemur from Madagascar

   https://doi.org/10.1371/journal.pbio.3003015  

   Wang, Richard J; Peña-García, Yadira; Raveendran, Muthuswamy; Harris, R Alan; Nguyen, Thuy-Trang; Gingras, Marie-Claude; Wu, Yifan; Perez, Lesette; Yoder, Anne D; Simmons, Joe H; et al (February 2025, PLOS Biology)

   Hurst, Laurence D (Ed.)

   Every mammal studied to date has been found to have a male mutation bias: male parents transmit more de novo mutations to offspring than female parents, contributing increasingly more mutations with age. Although male-biased mutation has been studied for more than 75 years, its causes are still debated. One obstacle to understanding this pattern is its near universality—without variation in mutation bias, it is difficult to find an underlying cause. Here, we present new data on multiple pedigrees from two primate species: aye-ayes (Daubentonia madagascariensis), a member of the strepsirrhine primates, and olive baboons (Papio anubis). In stark contrast to the pattern found across mammals, we find a much larger effect of maternal age than paternal age on mutation rates in the aye-aye. In addition, older aye-aye mothers transmit substantially more mutations than older fathers. We carry out both computational and experimental validation of our results, contrasting them with results from baboons and other primates using the same methodologies. Further, we analyze a set of DNA repair and replication genes to identify candidate mutations that may be responsible for the change in mutation bias observed in aye-ayes. Our results demonstrate that mutation bias is not an immutable trait, but rather one that can evolve between closely related species. Further work on aye-ayes (and possibly other lemuriform primates) should help to explain the molecular basis for sex-biased mutation. 

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5. Beyond Robotics, Materials, and Sensing: Unveiling Bioinspiration in Nondestructive Evaluation From “Nature’s NDE Specialists”

   https://doi.org/10.32548/2025.me-04490  

   Dehghan-Niri, Ehsan (April 2025, Materials Evaluation)

   Dehghan-Niri, Ehsan (Ed.)

   While bioinspiration research has led to advancements in fields such as robotics, materials, sensing, and neural computation over the past few decades, its application to more mission-oriented tasks, like nondestructive testing/evaluation (NDT/E), remains largely unexplored. Bioinspiration in NDT/E offers innovative approaches to advance current technologies by drawing inspiration from natural systems that perform similar tasks or processes. This paper explores three unique biological systems—aye-ayes, termites, and red/arctic foxes—referred to as “nature’s NDE specialists.” These organisms have evolved specialized food foraging processes to detect, characterize, assess materials, and detect targets in their environments without disruption, mirroring the goals of NDT/E methods such as tap testing and leakage detection. By studying these specialized processes, we can pioneer new NDT/E technologies or advance the current ones, by means of enhancing reliability, sensitivity, adaptability, and accessibility in challenging environments. Additionally, integrating bioinspiration into NDT/E education can attract a new generation of students, creating opportunities to address the workforce challenges in the NDT/E field. 

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