For an innovative piece of materials science and electrical engineering, take a look at our most recent paper in the area of bioelectronics, published today in the current issue of Nature Electronics – “A Wirelessly Powered, Light-Controlled, Bioresorbable Stimulation System With Programmable Polyphasic Waveforms.” nature.com/articles/s41928-0…. Here, we introduce a scheme in which light illumination serves as a mechanism for precisely shaping the temporal and spatial profiles of electrical stimulation delivered to targeted tissues by a battery-free, flexible implant. The work includes not only detailed studies of all of the aspects in engineering science but also elaborate examples in advanced forms of control of cardiac rhythms and respiratory patterns, via cardiac pacing and phrenic nerve stimulation, respectively. The key to device operation is in the combined use of small-scale coils for radio frequency power transfer and miniaturized bipolar junction transistors for optical modulation – all constructed in materials that support high-performance operation but are uniquely defined by their ability to dissolve naturally and harmlessly inside the body following stable operation over a clinically relevant timeframe for treatment of temporary patient conditions. The paper is the result, primarily, of the efforts of a remarkably talented pair of former postdoctoral fellows in the group – Prof. Jong Uk Kim (now on the faculty at @SKKUni1398) and Prof. Seung Gi Seo (now on the faculty at Kumoh National Institute of Technology) – also with essential contributions from Dr. Hongkai Wang and Dr. Eric Rytkin in medically relevant demonstrations. Of course, the various roles of the many other co-authors were also very important. Key senior investigators include Prof. @IEfimov (cardiac), Prof. @ColinFranzMDphd (phrenic), Prof. Sung Hun Jin (BJT processing) and Prof. ZHENQIANG MA (BJT physics). Thanks to everyone for the great collaboration! Also, thanks to Prof. @JunChenLab for writing a nice News and Views perspectives piece on our work, published alongside our paper in this issue of Nature Electronics! nature.com/articles/s41928-0…

Really great informal get-together at the end of the first day of the MRS meeting. All former group members, all current faculty members – Jang-Ung Park (@yonsei_u), Dae-Hyeong Kim (@SeoulNatlUni ), Yeon Sik Choi (@yonsei_u), Hamed Arami (@ASU), Quansan Yang @QuansanYang (@UW), Jae-Woong Jeong (KAIST), Lan Yin (@Tsinghua_Uni), Seok Kim (@postech2020 ), Seung Yoon Ryu (@dongguk_univ), @XuejuW (@UConn), Jeonghyun Kim (Kwangwoon University @Kwangwoon_univ ), Keon Jae Lee (KAIST), @GT_HongYeo (@GeorgiaTech), Changsheng Wu (National University of Singapore), @XugroupUCSD (@UCSD), Tae-il Kim (Sungkyunkwan University) and Lizhi Xu (@HKUniversity). Also joining, former postdoc Kento Yamagishi @kento_yamagishi (staff scientist with Takao Someya @tsomeya, The University of Tokyo), visiting PhD student Xiao Xiao(National University of Singapore), and ‘honorary’ group member Prof. @JunChenLab (@UCLA). Incredible collection of young, high-powered researchers – a small subset of >150 former group members who are highly successful faculty at great research universities around the world: ~50 here in the US; ~60 in Korea; ~20 in China; and ~20 in Europe and Canada. Super fun to spend time together and talk about science, engineering, commercialization, current events and life in general! Thanks to Yeonsik for organizing!