mˈækəl ˈɔːlsoʊ dɪzˈaɪnd ˈeɪ "baɪˈɑːpsi hɑːɹpˈuːn", ɐ dˈɑːɹtlˈaɪk kəntɹˈæpʃən hiː ɐtˈætʃt tʊ ɐ sˈʌbmɚɹˌiːn ɪn ˈɔːɹdɚ tə kəlˈɛkt tˈɪʃuː sˈæmpəlz.
Mackal also designed a "biopsy harpoon", a dart-like contraption he attached to a submarine in order to collect tissue samples.