Mehmet Girayhan Say — Materials Scientist & Device Engineer

01 — About

Materials meet medicine

I am a KAW Repatriation Fellow at Chalmers University of Technology's Department of Microtechnology and Nanoscience (MC2), with a concurrent Research Affiliate appointment at MIT. My work centers on functional materials and devices that can interact with the body — from bioresorbable batteries to ingestible electronics platforms.

My doctoral training at Linköping University's Laboratory of Organic Electronics (LOE) under Profs. Magnus Berggren and Isak Engquist gave me deep expertise in organic electronics and printed device fabrication. My postdoctoral years in Prof. Giovanni Traverso's lab at MIT expanded this toward autonomous ingestible platforms and transient biomedical systems.

I hold a patent on biodegradable ingestible systems (PCT/US2025/049378) and have contributed to multiple research funding programmes, including the ARPA-H REO program. I serve as a reviewer for ACS, Science Advances, and multiple MDPI journals, and mentor students at Chalmers, MIT, and beyond.

Current Position KAW Repatriation Fellow Department of Microtechnology and Nanoscience (MC2)
Chalmers University of Technology
Host Lab: Prof. Maria Asplund
Feb 2026 – Present · Göteborg, Sweden

Research Affiliate Massachusetts Institute of Technology (MIT)
Mechanical Engineering Nov 2024 – March 2026

Postdoctoral Fellow Massachusetts Institute of Technology (MIT)
Traverso Lab Advisor: Prof. Giovanni Traverso · 2022–2024

PhD — Applied Physics Laboratory of Organic Electronics (LOE)
Linköping University, 2022 Thesis: Hybrid Materials for Wearable Electronics and Electrochemical Systems
Advisors: Prof. Magnus Berggren & Prof. Isak Engquist

Patent PCT/US2025/049378 · 2025 Biodegradable Ingestible Systems and Related Electronics

03 — Research

Research directions

— PILLAR 01

Bioresorbable & Transient Electronics

Developing electronic systems that safely dissolve in physiological environments after their diagnostic or therapeutic purpose is served. This work bridges materials chemistry, device engineering, and medicine — enabling a new generation of implants and ingestibles that leave no lasting trace in the body or the environment.

Bioresorbable Transient Devices Biodegradable

— PILLAR 02

Ingestible Bioelectronics

Designing swallowable devices that sense, communicate, and intervene within the gastrointestinal tract. These autonomous platforms combine wireless power, signal transduction, and biocompatible materials to address adherence, diagnostics, and localized therapy — pushing electronics into a space once reserved for pharmacology alone.

Ingestible GI Sensing Wireless

3D Printing

— PILLAR 03

Organic Energy Storage & Harvesting

Building printable, flexible, and biocompatible sources of power from conductive polymers and cellulose-based materials. From thin supercapacitors on paper to galvanic microcells that harvest energy in situ, this work enables self-powered wearable and implantable electronics — without rare metals or toxic chemistries.

PEDOT:PSS Supercapacitors Cellulose Energy Harvesting

3D Printing

— PILLAR 04

Skin & Wearable Electronics

Designing ultrathin, flexible, and conformable devices that sit on the skin — unobtrusively measuring biosignals, delivering stimulation, or indicating changes in state. By marrying soft substrates with printed electronics, this work extends the body's sensory and therapeutic reach into everyday life.

e-Skin Wearable Flexible Biosignals

05 — Publications

Selected work

Bioresorbable Batteries for Transient Ingestible BioelectronicsPillar 02 · Ingestible

M.G. Say, et al., G. Traverso

Nature Chemical Engineering, 2026 (in revision) · first author

Bioresorbable RFID capsule for assessing medication adherence (SAFARI)Pillar 01 · Bioresorbable

M.G. Say*, S.S. You*, Y. Chai, I. Moon, A. Erus, B.N. Muller, N. Fabian, A.M. Hayward, G. Traverso

Nature Communications, 2026, 17, 52 · *equal contribution

Translational Barriers of Continuous Monitoring Technologies for Preventative Medicine

J. Chen, P. Jastrzebska-Perfect, P. Chai, M.G. Say, J. Tu, W. Gao, F. Halperin, J. Korzenik, H-W. Huang, D. Katabi, G. Traverso

Nature Biomedical Engineering, 2025, 9, 1797

Bioelectronics for the Gastrointestinal Tract

O. Akoussi, M.G. Say, M.L. Cavestany, G. Schiavone, A.G. Gonzales, J-J. Lee, R. Owens, S. Park, G. Malliaras, S.P. Lacour, G. Traverso

Nature Biomedical Engineering Reviews, 2026 (invited review, accepted)

Bio-Inspired underwater adhesion for soft substrates

T. Kang, J.A. Gomez, A.M. Ross, A. Kirtane, M. Zhao, Y. Cai, …, M.G. Say, C.P. Kenaley, G. Traverso

Nature, 2025, 643, 1271

Ultrathin indium tin oxide accumulation mode electrolyte-gated transistors for bioelectronicsPillar 04 · Skin

L. Migliaccio*, M.G. Say*, G. Pathak, I. Gablech, J. Brodsky, M. Berggren, M. Donahue, E. Glowacki

Advanced Materials Technologies, 2024, 2302219

Study on the Rectification of Ionic Diode Based on Cross-Linked Nanocellulose Bipolar Membranes

H. Yang, J. Edberg, M.G. Say, …, I. Engquist

Biomacromolecules, 2024, 25(3), 1933

Direct Ink Writing of Nanocellulose and PEDOT:PSS for Flexible Electronic Patterned and Supercapacitor Papers

M. Lay, M.G. Say, I. Engquist

Advanced Materials Technologies, 2023, 8(18), 2300652

Nanocellulose and PEDOT:PSS composites and their applications

R. Brooke, M. Lay, K. Jain, H. Francon, M.G. Say, D. Belaineh, …, I. Engquist

Polymer Reviews, 2023, 63(2), 437–477

Ultrathin polymer electrochemical microcapacitors for on-chip and flexible electronics

M.G. Say, M.J. Donahue, R. Kroon, M. Berggren, I. Engquist

Organic Electronics, 2023, 115, 106751

Scalable paper supercapacitors for printed wearable electronicsPillar 03 · Energy

M.G. Say, C.J. Brett, J. Edberg, S.V. Roth, L.D. Söderberg, I. Engquist, M. Berggren

ACS Applied Materials & Interfaces, 2022, 14(50), 55850–55863

Upscalable ultra thick rayon carbon felt based hybrid organic-inorganic electrodes for high energy density supercapacitors

X. Wang, M.G. Say, R. Brooke, V. Beni, D. Nilsson, R. Lassnig, …, I. Engquist

Energy Storage, 2022, 4(5), e348

Printable carbon-based supercapacitors reinforced with cellulose and conductive polymers

D. Belaineh, R. Brooke, N. Sani, M.G. Say, K.M.O. Håkansson, I. Engquist, M. Berggren, J. Edberg

Journal of Energy Storage, 2022, 50, 104224

Ultrathin paper micro-supercapacitors for electronic skin applications

M.G. Say, I. Sahalianov, R. Brooke, L. Migliaccio, E. Glowacki, M. Berggren, M. Donahue, I. Engquist

Advanced Materials Technologies, 2022, 2101420

The effect of crosslinking on ion transport properties of nanocellulose based membranes

H. Yang, J. Edberg, V. Gueskine, M. Vagin, M.G. Say, J. Erlandsson, L. Wågberg, X. Crispin, I. Engquist, M. Berggren

Carbohydrate Polymers, 2022, 278, 118838

Volumetric Double-Layer Charge Storage in Composites Based on Conducting Polymer PEDOT and Cellulose

I. Sahalianov*, M.G. Say*, O.S. Abdullaeva, F. Ahmed, E. Glowacki, I. Engquist, M. Berggren, I. Zozoulenko

ACS Applied Energy Materials, 2021, 4, 8629

In situ and non-cytotoxic crosslinking strategy for 3D bioprintable biomaterials

Y. Sumbelli, S.E. Diltemiz, M.G. Say, O.B. Unluer, A. Ersoz, R. Say

Soft Matter, 2021, 17(4), 1008

Spray Coated Paper Supercapacitors

M.G. Say, R. Brooke, J. Edberg, A. Grimoldi, D. Belaineh, I. Engquist, M. Berggren

npj Flexible Electronics, 2020, 4, 14

A powerful combination in designing polymeric scaffolds: 3D bioprinting and cryogelation

O.B. Unluer, S.E. Diltemiz, M.G. Say, D. Hur, R. Say, A. Ersoz

International Journal of Polymeric Materials and Polymeric Biomaterials, 2020

Supercapacitors on Demand: Printed energy storage devices with adaptable design

R. Brooke, J. Edberg, M.G. Say, A. Sawatdee, A. Grimoldi, J. Åhlin, G. Gustafsson, M. Berggren, I. Engquist

Flexible and Printed Electronics, 2019, 4, 015006

3D Micropatterned All-Flexible Microfluidic Platform for Microwave-Assisted Flow Organic Synthesis

D. Hur, M.G. Say, S.E. Diltemiz, F. Duman, A. Ersöz, R. Say

ChemPlusChem, 2018, 83, 42

Ferritin based bionanocages as novel biomemory device concept

Ş.N.K. Elmas, R. Güzel, M.G. Say, A. Ersoz, R. Say

Biosensors and Bioelectronics, 2017, 103, 19

A motion- and sound-activated, 3D-printed, chalcogenide-based triboelectric nanogenerator

M. Kanik, M.G. Say, B. Daglar, A.F. Yavuz, M.H. Dolas, M.M. El-Ashry, M. Bayindir

Advanced Materials, 2015, 27, 2367

Kinect based intelligent wheelchair navigation with potential fields

M. Ozcelikors, A. Coskun, M.G. Say, U. Yayan, M. Akcakoca, A. Yazici

Innovations in Intelligent Systems and Applications (INISTA), 2014, 330

06 — Teaching & Mentorship

Developing the next generation

I approach mentorship as the most durable output of academic work. A paper lasts; a well-trained scientist multiplies. At MIT, I supervised six master's and undergraduate research thesis students across mechanical engineering, materials science, and biomedical engineering — all of whom went on to positions at MIT, Stanford, or Northeastern.

I also mentored more than 20 UROP (Undergraduate Research Opportunities Program) students, many of whom were publishing first research experiences. In Sweden, I am building a mentorship practice grounded in technical rigour, intellectual independence, and collaborative research culture.

My teaching interest spans device physics, materials characterisation, printed electronics, and the translation of laboratory discoveries toward clinically meaningful systems — subjects I aim to develop into formal courses at MC2.

Thesis students supervised

20+

UROP students mentored

Countries of placement

100%

Thesis students placed

Mehmet
Girayhan
Say

Materials meet medicine

Recent highlights

Research directions

Research support

Selected work

Developing the next generation